I bought Point Lookout and Mothership Zeta a few months ago, but never bothered to play them since I'd accidentally deleted all my high level save games.  What level should I be to go into these 2 DLCs and not expect to get raped?

Well, for Mothership zeta it doesn't really matter, I did it as a new guy for an achievement, so you can do it frome the start, but I would recommend that for point lookout, that you are at least a level 7 or like a 10, there's some harder parts in it.
 
It shouldn't really matter all that much either way, but for Point lookout I would have a higher level or lots of stimpacks. 
Just a couple of tough spots is all.

They scale to your level so it doesn't really matter

" They scale to your level so it doesn't really matter "

I started the pitt as soon as i could because there is some useful stuff in it.

I almost always kick off my games w/ Op Anchorage for the Stealth Suit and that knock-back Sniper gun (forget the name now). I found Point Look Out to be unfriendly to someone fresh out of the vault. Like MonkeyMelon said somewhere around 7-10 you should have some gear and abilities that will help you tackle PLO.

" They scale to your level so it doesn't really matter "

I actually find, with a new character, that the first thing to do is Operation Anchorage. You come out with some badass power armour that you don't need training for, in other words, you get one of the best sets of armour in the game first thing, and you'll probably come out 7-10 levels higher depending on how you did everything.

do operation anchorage and you'll get some sweet loot off the bat.
 
*err nvm

Would you guys say that your level entering The Pitt doesn't really matter?