Default [Q] Few questions...?

Hi, first off all, I'm looking for a basic ROM, don't need any fancy feautures or anything the most important thing to me is that its stable and everything works and the battery life is good. All I'll be using the phone for is calling people, texting, Facebook, Snapchat and maybe a few other things... No gaming or anything just basic things...

What would you recommend? I'm currently trying cm11 but looking at aosp, would this be better for me?

I have a nexus 7 and love the plain android...

Also does anyone else have lag when unlocking/waking up the phone? Soft key buttons light up but it doesn't come on for about 2 or 3 seconds?

And one more thing, is about 555mb of ram normal?

Much help and advice would be appreciated...

Thanks.