I haven't been on facebook in like a year and a half..questions?

[OKShibbby]

I know its way different now i guess?..
but i have like over 300 notification emails built up by now
(even after i asked facebook to stop)

so

-first can anyone im "friends" with tell when i logged on last, or if i am logged on at the moment?
(if i sign on)
-will all the notifications i check show up on my wall? if so is there some way i can prevent that..
-and last, one email notification, said i was tagged in like 176 photos or something. this really scared me. because i never let people photograph me...that i know of...so i don't know what i might be running into. how do you untag yourself in photos?

basically will it be possible for me to log on, check my stuff, maybe look at some old friends pages that i havent seen or spoken to in a very long time because i kind of dissapeared..
all without anyone out there knowing the difference at all?

i really, REALLY need to be sure this can all go my way before i do anything.
Please be positive before you answer.

Thankyou.