Purchase from Amazon and on activation window said (RU) ??!?!?!?

Don't be Russian to conclusions now.

It's a glitch in Steam. You don't really have anything to worry about if you didn't use proxies or VPN services to activate the key. And from the context, I guess it's fair to say you didn't.

isn't it the version with dlc included?

Check under your account details.

Licenses and subscriptions

I had the same with a couple of purchases for the same game a while back. The DLCs, if included as separate keys, are unneeded as the version you activated includes both, which is why there has been a number of giveaways for the DLCs.

Anyway, despite what it said during activation, you will be able to play the game normally, with English text.

ahhh great, strange still! nah i dont use VPN cause it is officially restricted!

I had that too ^^ with the excact game

yeah, when I redeem the RENEGADE OPS key brought from Amazon, it said RU in the detail too. And it included all the DLCs, may be this is the different of the RU version.
Havent got any issue so far. Havent installed it yet too