If anyone has time, it would be very nice with a mod that let you play through the original kotor, with the features from tsl, like the baldur's gate tutu mod for baldur's gate 2. It'll properbly take a lot of time, but it would be really fun to play.

It all depends on what you mean by "features"...

If you are referring to porting things like models, and textures this we cannot do because it violates the law, and as such Forum Rule #14. (http://64.20.36.211/showthread.php?t=127725)

Like I said it all depends on what you mean by features.

I think whatever you want done cannot be done without breaking the rules but then again it all depends on what you mean by "features" as RedHawke said =/

Some of its hardcoded into KotOR.

By features, I mean force powers, feats, lvl cap removal and Influence.

By features, I mean force powers, feats, lvl cap removal and Influence.
In that case most of the answers are a simple no...

With the exception of Force Powers, all the other game features you mention are hard coded, or simply don't exist in KOTOR I and cannot be added or modded.

And some of the new Force Powers in TSL, I believe, make use of scripting calls that don't exist in KOTOR I. So some of them might be impossible too. Also note that with powers like Force Crush you would also lack the animations as well as they too don't exist in KOTOR I.

So only the TSL Force Powers that could be scripted into KOTOR I would be possible, even still it wouldn't look like it does in TSL.