will be leveling my old 90 rogue to 100, and questions (PVP)

[SlayAllDay]

Hai there everyone
So I literally just returned to wow and decided I want to level my rogue that is still level 90 from last expansion - to 100 and go PVP like all my other characters.
(I have 3 level 100s and so many others just chillin at level 90 right now, so I dont need much advice on how to level or anything lol) but I need advice as to what you think about subtlety? I Honestly havent played a sub rogue since cataclysm and I used to LOVEEEEEE it back then, and now everything has really changed on the rogues (or so it seems).

How is sub rogue doing this PVP season? Should I maybe try a different spec? I want to play the most fun/best option for world PVP, arenas, and BGs.

If you guys think I should just play sub, which is what I know how to play best - are the stats different that I need to stack for such as crit/haste/etc?
Would love to hear how my fellow wow players are playing their rogues ^_^

Sorry so many questions lol I work a lot and it's hard to just go research everything when I can just ask fellow players

also, any suggestions on which race i might should change to? my rogue is a gorgeous undead, but might want to play something different.