So you grant a bonus for one kind of player skill ("tactical considerations").
But not another ("roleplay"/social intelligence/me talk pretty sometime).
Does the PC of the player using "tactics" need a minimum INT score, ie so as not to dump-stat INT?
XP bonuses are nice, but I've found the thing that's most important to players is the feeling of accomplishment they get from solving the immediate challenge. They want to know they did something that helped the team "win". Allowing for this --at a table with people with different abilities/levels of social savvy-- is more important to me than combating dump-statting.
Speaking in character (#1) is a style preference. #4 is equally as valid, in being descriptive and still roleplaying, just not speaking in character.
The problem with judging on speaking with character is that the evaluation is subjective, and prone to double-modifying the situation.
If you have a low CHA and you play it as the silent quiet type, you may get through more situations than somebody who truly hams it up and acts all creepy and dislikable.
Without even rolling, the GM is going to react negatively to the latter kind of PC, even though they both have the same stat.
This in turn gets amplified when it comes to actually doing any kind of social skill check. The GM will inherently bias against the performance.
My recommendation is to isolate that. The performance is great, give them XP for it if it is "in character" But strictly follow what the numbers say, not the performance. The perfomance shows intent. That's it.
As for your comment about giving a bonus for tactical (perhaps I should have said situational) factors also being a player skill, I don't have a problem with that.
I already accept that not all players are created equal. A tactical genius will do smarter things with his fighter than the village idiot, despite both of them having the same stats.
Somebody who is trying to bluff the guard while wearing the wrong clothes, covered in blood, stating blatant lies is an idiot, and is going to suffer a situational penalty. But not for roleplaying. For being a tactical idiot. The same way the player gets hit with AoOs and rushes into fights that get him killed.
Remember, I do not see the rules as some sort of Great Equalizer for stupid people and smart people, shy people or social people.
My approach levels out the abjudication of speaking in character, by excising it from the resolution mechanic. It's not for the shy guy's benefit or detriment.
Note: I don't see a reason why the Shy Guy would be prone to screwing up handling a Bluff check by declaring how he approaches the situation. It's more probable that Undiplomatic Guy will screw it up by being a jerk, when he should have been deferrential. That's a situational modifier, not by his speaking in character, but by the very intent that is evident in his approach.