Root couple of questions (screenshot attached)

[chasen]

I bought my Tab new (sort-of). Bought it from a guy who purchased it, rooted it and did other stuff (that i don't know) then sold it to me.

attached is a screen shot.
Questions:

what rom am i running?
what kernel?
how do i change these as there's no rom manager installed?
what else can you tell me from the screenshot that is important?

thanks in advance!!