Okay, since I am the synthesist expert, I should throw my two bits in. I've been a little busy lately.
As to the claws and bite, I see things this way. You have the summoner's form. It has its attack methods. That gets overlaid with an eidolon suit. That suit is on the outside. Only outside attack methods are usable. But then, as an example, we have the "a sorcerer grows a set of claws for 1 round" that adds attack forms, outside of the current body. So, temporary attack methods from the inner person can be added and used. Another example is the Dragon Disciple's wings at 9th level. Those would be temporary adds to the outside, so they count. Permanent attack methods of the original form do not, as they are engulfed. So, yes, paragraph one of the wiki applies, and paragraph four applies. But, in a very convoluted manor.
The tiefling in question had permanent claws, and that was being enveloped by the eidolon suit. With some discussion and compromise, I would have probably allowed the claws. The whole area is a bit fuzzy.
Another thing that sat a little sour with me is the "my wings and claws are just wispy shadows, until I actually need them." Both of the traits to get them actually give permanent attributes. The mixed blood fluff trying to negate the drawbacks of the traits of wings and claws, when there isn't a "shadow form" ability in the sheet is slightly annoying. The proper method is that they are solid all the time, and get engulfed by the eidolon suit. The tail also gets engulfed. I think that was implied.
My quip about the darts? They are just such a poor weapon choice. A sling has 2.5x the distance reach for the same damage. A spear is going to have 50% more damage. And, in non-fused form, the dart is going to be doing 1d4-2 damage. Well, that is 50/50 as to if you are only doing non-lethal damage. Yes, she has several summon monster SLAs to use, but she cannot totally rely on that to get her out of every situation. As an example, we had a Lore Oracle character back about six months ago that wanted to throw tarot cards as shuriken, with a strength penalty. She ended up as her only weapon only able to do 1 non-lethal damage, unless she could crit. I flat out said "No, I am not approving that character" on the reason that she would be a drain on the party and could not contribute in a fight. It would have been one thing if she was a healer, but just a knowledge bot that can't fight, well we have bards for that.
Another one, The Cart: The cart weighs 200 lbs. She is stuffing it with 234 lbs of stuff. So, 434 lbs to "push or drag" as the the tables would call it. So, Rose's 7 strength allows her to pull a cart with a combined weight of 350 lbs. If the eidolon is not there for the extra oomf, she is stuck where she stands. That is, unless she abandons the cart and her possessions.
The shield issue. The character is not proficient with the weapon. A throwing shield is a weapon. Therefore, she doesn't get to use any of the special properties that come with proficiency. Therefore, its use becomes that as a normal shield, not a throwing one. That means dropping it becomes a move action. Ding. Breaks the chain of actions being put together.
But, my issue with it was the "I can chain all this together" and actually come out with something so poor. That same 300 gp spent on the shield could have been spent on twelve scrolls of Mage Armor, achieving twice the armor bonus. Characters level a bit faster than normal in LPF because we give you Time Based XP and GP for the days you are in an adventure. So, roughly 6-7 fights will get you to 2nd level. Since some of those fights will be in the same hour, 12 scrolls are going to carry you on into third level. So, if you did things in the optimal fashion, it would be 12 scrolls of Mage Armor, take Shield as one of your two spells, and rock an AC 24 for every fight until 3rd level if you spend the first round buffing. That is a whole lot better than the AC 18 she was trying to achieve. To string together a chain that is very grey area, and then get results that are quite inferior to known good tactics, that looks like ... well ... I don't know how to finish this sentence.
Emily on the other hand. She is stacking her strengths. High charisma. A racial bonus to charisma. A class that uses charisma as its focus stat. Using the skilled evolution effectively. Realizing that the skilled is actually a racial bonus and doing the proper replacement. Good trait choice. Yeah, she is rocking a +18 Diplomacy check. As a GM, I am cringing, but I know I gotta suck it up. As a player, I am going "Bravo!"
Yes. Systole stomped harder than he should have. I think I can safely say that the two of you have seen him at his worst. He is normally a cuddly goofball, unless he has been drinking. Then, well, can we say 'entertaining'? But, you have a 1 in 4 chance of him being your GM in your first game. Over the first 10 levels of your career, he will be in your party or a GM with a 99% likelihood. He stated things like he did so you don't get a month or six in and then find out there might be a conflict when you thought all was peachy.
Now for some friendly advice: The synthesist may not always be in fused form. Tasanto has been in a game for five months, or three days in game, and has spent the effectively first three encounters in an unfused state. He did get to frighten a couple peasants for a bit, but has spent most of his time out of form. Sometimes a big cattaur is not the best thing to be when you are trying to be inconspicuous. So, being a viable character when the beast is not around is highly suggested.
Rose needs some work. She can be salvaged, but as a synthesist, she is running fairly suboptimal right now. When was the last time you saw a dwarven sorcerer? Yeah, she is in that vein. Then again, I have a multi-classed mermaid synthesist. And my triple classes summoner, nobody likes to talk about him. So, suboptimal is not a, or
the, problem. Stacking together a bunch of corner cases to get a result that could be argued, well that is where the feathers got ruffled. Start basic. Make sure your strengths are enhanced by the choices, and adding one thing does not block or hinder another. I mean, I couldn't see any reason to take the wings. They get smothered into the suit.
Well, that is getting long enough. Time to hit the button.