Gah.. boards ate my post.. that will cause me to be much less nice in this one because of time constraints 
Swallow whole: find a rules reference saying that you cannot get a weapon while in the beasts gut and that will be a rule that will kill most pc's. As in my experience most pc's dont go around holding a light weapon anyway (wizards are usually quarterstaff or crossbow, clerics usually some sort of sword and board combo with their dieties weapon or a nice mace, archers have bows, melee types have so many different choices it is hard to say which path they will go.. especially with the substandard twf)
Basilisk said I am trying to have it both ways, I am not, the thf already do so there is no need for me to try anything.
They can have a shield (via animated shield or a spell or possibly feats) and it costs less than the twf under most circumstances.
weapon (2k)*(+#)^2
armor (1k)*(+#)^2
thf = weapon + animated shield = (2k)*(+X)^2 + (1k)*(+Y+2)^2
twf = 2 weapons = 2*(2k)*(+X)^2
twf (shield) = 2 weapons + shield = 2*(2k)*(+X)^2 + (1k)*(+Y)^2
(X,Y)
thf (2,2) = 8k + 16k = 24k
twf (2,0) = 2*8k = 16k
twf (shield) (2,2) = 2*8k + 4k = 20k
thf (4,4) = 32k + 36k = 68k
twf (4,0) = 2*32k = 72k
twf (shield) (4,4) = 2*32k + 16k = 88k
thf (10,8) = 200k + 100k = 300k
twf (10,0) = 2*200k = 400k
twf (shield) (10,10) = 2*200k + 100k = 500k
Now you could cut down the plus's on the twf style in order to make the costs more even in gp value, but then you fall even farther behind in offense, defense, or both.
Roleplaying choices deal with doing what you want to with a character no matter the cost. Chooseing twf style and going with it no matter if it is inferior or not constitutes a roleplaying choice, if you were only going by the numbers then you wouldnt have choosen it so it cant be a mechanics choice.
Twf is flavorful, just as much as thf, sword and board, or any other style out there. They all have their own flavor, now they all just need to have their own strengths and weaknesses across the board to all be viable choices. In order to make the choice still roleplaying, but useful no matter what you pick, or a mechanics choice in trying to be slightly better in one area. Not a choice of, 'do I want to really suck at everything but look cool or do I want to contribute more to the group'
As soon as you actually point out some parts of twf that are 'more' flexible than thf I'll look them over, until then though....
Sneak attack is impressive, but at higher levels it rarely comes into play. Almost all creatures are resistant or immune, or can become resistant or immune if they desire to do so.
Almost everything I've said above starts to kick in at higher levels, if your games never go above 8th level then you might not see a problem. This is because the cost:benefit ratio is still not too bad. At the lower plus's for equipment the cost disparities hurt a little but not much, the feat cost is only 1 so far so that isnt too bad, and there really arent many creatures with DR.
At the higher levels though it really sucks, you just keep hitting over and over again the diminishing returns for your money and feats which show up in damage potential, defense, and other areas.

Swallow whole: find a rules reference saying that you cannot get a weapon while in the beasts gut and that will be a rule that will kill most pc's. As in my experience most pc's dont go around holding a light weapon anyway (wizards are usually quarterstaff or crossbow, clerics usually some sort of sword and board combo with their dieties weapon or a nice mace, archers have bows, melee types have so many different choices it is hard to say which path they will go.. especially with the substandard twf)
Basilisk said I am trying to have it both ways, I am not, the thf already do so there is no need for me to try anything.
They can have a shield (via animated shield or a spell or possibly feats) and it costs less than the twf under most circumstances.
weapon (2k)*(+#)^2
armor (1k)*(+#)^2
thf = weapon + animated shield = (2k)*(+X)^2 + (1k)*(+Y+2)^2
twf = 2 weapons = 2*(2k)*(+X)^2
twf (shield) = 2 weapons + shield = 2*(2k)*(+X)^2 + (1k)*(+Y)^2
(X,Y)
thf (2,2) = 8k + 16k = 24k
twf (2,0) = 2*8k = 16k
twf (shield) (2,2) = 2*8k + 4k = 20k
thf (4,4) = 32k + 36k = 68k
twf (4,0) = 2*32k = 72k
twf (shield) (4,4) = 2*32k + 16k = 88k
thf (10,8) = 200k + 100k = 300k
twf (10,0) = 2*200k = 400k
twf (shield) (10,10) = 2*200k + 100k = 500k
Now you could cut down the plus's on the twf style in order to make the costs more even in gp value, but then you fall even farther behind in offense, defense, or both.
Roleplaying choices deal with doing what you want to with a character no matter the cost. Chooseing twf style and going with it no matter if it is inferior or not constitutes a roleplaying choice, if you were only going by the numbers then you wouldnt have choosen it so it cant be a mechanics choice.
Twf is flavorful, just as much as thf, sword and board, or any other style out there. They all have their own flavor, now they all just need to have their own strengths and weaknesses across the board to all be viable choices. In order to make the choice still roleplaying, but useful no matter what you pick, or a mechanics choice in trying to be slightly better in one area. Not a choice of, 'do I want to really suck at everything but look cool or do I want to contribute more to the group'
As soon as you actually point out some parts of twf that are 'more' flexible than thf I'll look them over, until then though....
Sneak attack is impressive, but at higher levels it rarely comes into play. Almost all creatures are resistant or immune, or can become resistant or immune if they desire to do so.
Almost everything I've said above starts to kick in at higher levels, if your games never go above 8th level then you might not see a problem. This is because the cost:benefit ratio is still not too bad. At the lower plus's for equipment the cost disparities hurt a little but not much, the feat cost is only 1 so far so that isnt too bad, and there really arent many creatures with DR.
At the higher levels though it really sucks, you just keep hitting over and over again the diminishing returns for your money and feats which show up in damage potential, defense, and other areas.