1. When playing your favorite RPG as player or GM/DM, how much suspension of disbelief do you require? For instance, as a player do you prefer to have a character and game world that could make "sense" or it really doesn't matter as long as I am having fun and it is not too abstract and gamey.
Depends on what you mean by "make sense." If by "make sense" you mean "realistic" as in adheres to the real world, then that doesn't matter too much to me, for the following reasons:
1a. There are a lot of aspects of the game (e.g. magic and dragons) that are unrealistic by design. I don't see any reason to demand "realism" with respect to Aspect A of the game but not demand realism in Aspect B, just because Aspect B has the label "magic" attached to it and Aspect A doesn't.
1b. A lot of the time, events in the game (like medieval combat and animal training) are so far outside my real-life experence that I am not qualified to know what is realistic, and DMs and players can have very different "common sense" ideas on what is realistic. (If you don't believe me, just watch a few episodes of MythBusters.) So any system which requires DMs and players to make lots of judgements about what is "realistic" can lead to arguments.
However, the area where "make sense" does come into play is internal consistency: making sure that any changes affect the world in the ways you would expect.
For instance, consider the ease of healing in 4e - where warlords can make unconscious allies stand up by shouting at them, and everyone heals to full after 8 hours of sleep. These don't bother me in themselves. It's perfectly reasonable to me that the "supernatural" warlord healing ability and the 8-hour regeneration are just part of how the D+D world works, in the same way that wizards hurling fireballs are just part of how the D+D world works. But if that is accepted, its consequences should logically follow. For instance, there would be no medical facilities in the game world (except if they were needed to cure diseases, which don't auto-heal after 8 hours), and safety precautions would be much more lax, since they would be less necessary. If one asserted that only PCs get this "auto-heal" ability, then the above consequences would not happen, but there would be others - the residents of the world would notice that certain members of their population had a particularly powerful ability to heal themselves, and they would be very interested in why that is the case and how to use it to their advantage.
2. How much meta-talk at the game table do you like? For instance as GM/DM do you like your players in-character most of the time or do you like talk about mechanics and the best way to use them? How much do you allow?
I believe that talking about mechanics is not always "meta-talk." For example, I am playing in a HERO System campaign, and my character is a "gadgeteer" with the ability to reconfigure his gadgets in the field. The way this is implemented in-game is with a "variable power pool", where you have a certain number of "points" that you can allocate to powers, and there is a point system that you can use to build powers on the fly by starting with a base power and adding on "advantages" and "limitations." So in-game, I can talk about mechanics - "okay guys, if I give the invisibility to all of you, then I won't be able to afford the 'zero endurance cost' advantage, so it will cost me X endurance per turn, and I have Y endurance and recover Z each turn, so I can maintain it for W turns at most, unless someone can give me extra endurance, etc. etc. etc."
Now the thing is, what I'm doing here - using the list of parts (powers and advantages) with known specifications (the mechanics) and figuring out how to put them together to achieve what I want, while taking into account design limitations, power consumption calculations, etc. is
exactly what real engineers do. So I don't see that talking about mechanics is not roleplaying - in that case I see it as the opposite.
3. Do you mind if the mechanics get in the way of the story at times? For instance, is it ok if you cannot form "real life" tactics with the game mechanics?
This goes back to #1. I don't mind if you can't form "real life tactics" with the game mechanics, because most of the time I wouldn't know what "real life tactics" are in the first place, and in any case, with the world so much different than ours there's not much reason to believe that "real life tactics" will work in the first place. As for 'story', I think that if you want to include an element of the story that conflicts with the mechanics, it makes more sense to change the mechanics, otherwise you end up with conflicting expectations. For example, let's say the story is about investigating a "one shot one kill" assassination, but the rules don't allow that because the number of hit points the target has is more than the maximum amount of damage any of the perp's attacks does. Then the players might go off in a wild goose chase the wrong direction, assuming that there had to have been something else going on because there's no way it could have happened the way it did. You could of course tell the players "the rules don't apply here," but that might give away the information, and in any case then players are going to constantly ask what they can assume about the rules when.
4. What level of mechanical "robustness" does the game feel right at? Is it broad easily applied rules that stay out of the way or more detailed rules that have more individual application?
The rules I prefer are rules that are as general as possible, but can still be applied unambiguously to specific situations. A real life example is Newton's laws of physics - they are very general in that they can be applied to almost any physical system that you will encounter in everyday life, but they are specific in that given a physical system, you can write down the equations and they will give you a specific solution.
A good in-game example is the Hero System's rules for strength. The rules for strength state that for any X >= 5, a strength score of X represents the amount of force required to lift (25 * 2^(X/5)) kilograms, and is enough to inflict (X/5)d6 damage. Also, in a contest of strength, each player rolls their strength dice and whoever has the highest score wins - so if A is grabbing B, A has a strength of 20 and B has a strength of 15, and B wants to get out of the grab, he rolls 3d6 to try to beat A's 4d6.*
Note that with this information, it is possible to derive a lot else:
- Rules for being damaged by an object crushing you: the force caused by the falling object crushing you is just the force of gravity on that object, so it has strength equal to the amount needed to lift it. So just roll damage equal to the strength corresponding to the object's mass (so a 200 kg object would have strength 15, and do 3d6 damage.) And since it is continuous, do that each round.
- Getting out from under an object crushing you: Make a contest (as described above) against a strength corresponding to the object's weight.
- Seeing if an object can support your weight: Roll the damage for the strength corresponding to your weight against the object (objects have "PD and ED" - which acts as damage reduction - and "BODY" - which acts as hit points) each round. Just like being crushed, except it's the object which is being crushed rather than a person.
- Throwing an object at someone: The force is equal to your strength, so just roll your strength damage if it hits. If the object has something that lets it do more damage than normal (like a throwing knife coated with poison) that's an extra effect that you buy as a power.
- Telekinesis: There's a telekinesis power, which is rated according to effective strength, so you can, for example, buy 25 strength worth of telekinesis. Then anything you can do with 25 strength normally, you can do at range with that telekinesis. So the telekinesis rules effectively inherit from the normal strength rules, so you don't need separate rules for each thing you can do with telekinesis (grab someone, steal his weapon, push him over a cliff, etc.)
The overall point is that you don't have to remember all these rules - you can just apply the general rule to each situation, and get the more specific rule.
*If you've played HERO System, you'll notice that you don't actually count up dice as normal, you could up the "Normal Damage BODY" on those dice. But that isn't really relevant to this discussion, so I won't go into it further.