Re-leveling

If I re-level, do I lose the bonuses from the tombs of knowledge? I am a fighter weapon master and might relevel to pick a different weapon specialization to take advantage of a special weapon I found. But I might not if I lose my +3 strength and constitution bonuses(the +3 strength is really nice for my warhulk.)

Another question. Where would there be a good place to get some items identified? I am building up quite a collection of items.

Bonuses from tomes (and warhulk, for that matter) will stick with you through relevel, so no worries there.

As for item identification, the easiest way to go is to seek out an altar to Kalas, which will identify all of your items for a donation of 5000 gp (there's one in the Vale). Alternatively, you can always tug on the sleeve of a passing bard or wizard; even the evil ones are usually pretty helpful like that.