Is there any way to wear BoS PA without everybody and their brother attacking me? =S

You could do arcade's quest.. Gannon family power armor and tesla armor, with no faction problems from wearing the armor.

Well, I really want to wear BoS PA, but I'm getting tired of killing the NCR

Create a truce between the NCR and BoS. Doing this requires MacNamara as the BoS Elder though.

This could work as well... Good luck.

Do Veronica's companion quest by convincing her to stay with the Followers... You get to kill three BoS paladins.

Do still in the dark and make the ncr and brotherhood come to a truce and the ncr won't attack you.

Like others said, if you complete still in the dark with McNamara and make a truce, you can wear the brotherhood T-51b without getting shot, although Legion will always shoot you with that power armor and there is no way to stay on good terms with them wearing it.

I can understand why you want to wear the Brotherhood T-51b, cause it looks righteous, unlike that ugly green [censored] on the default T-51b, looks like a flock of birds flew by and pooped on the suit...seriously.

How much DT does the Brotherhood power armour have?

Because in Mako Zlakololofiw's video the BoS PA had 70 DT !!

Easy find just T-51b power armour. There are suits that are none-faction related.

http://fallout.wikia.com/wiki/T-51b_power_armor_(Fallout:_New_Vegas)