There are a few outfits in the game that replace everything you are wearing. I.e. Kellogs outfit, that I think look awesome and I'd love to use but can't because you can't upgrade them at all. However I can upgrade a dress with ballistic weave. I wish they would change it, that waybif you do find something you like, you can make it decent.

I think it was designed so clothing that normally doesn't have an armour rating can be upgraded to provide at least some protection eg suits, dresses etc. Although there are a few exceptions when it comes to ballistic weave

Only generic apparel can have ballistic weave. Unique items like Kellogg's outfit can't. The most you can gain with ballistic weave is by adding it to an undergarment and a hat, giving you 220 total damage resistance. This is in addition to the arm, leg, and chest armor that you wear on top of them. A full set of heavy synth armor modded to the max gives you another 140 DR, a total of about 360.

Not true. There are several unique armors one can weave. Lorenzo's suit for one.

http://fallout.wikia.com/wiki/Ballistic_weave

Me too.

I would upgrade the Drifter's Outfit and wear that. I think it looks pretty cool. I would also upgrade the Silver Shroud suit and hat. Or at least the hat.

I think the concept is probably to do with going incognito. Being a RR agent, but looking like everyone else. For example, Deacon (the clothes horse ninja) is always swapping out to some different outfit that I presume is armored up with BW.