I'm sorry to hear about that....a lot of us are paranoid about our precious iD L's, lol.
I own a regular Japanese iD L and a 15th Anniversary iD L, and as most people here who know me somewhat probably know, the regular did break about five months ago (from accidental dropping, must've dropped it a bit too hard and one of the important parts broke or something).
In terms of screen protectors, I wouldn't recommend wiping it, because then the dust and stuff can get stuck in the edges. Instead, I found that a TT member's idea works very well: get a piece of scotch tape, stick it down on the screen, press, and then peel it off. I wouldn't worry too much about the screen, though.
Also, another idea, if it's possible, is to check out Japanese dollar stores or other Asian ones for iPod screen protectors. They're normally very inexpensive (should be less than $5) and work quite well as long as you get the measurements for cutting it right.
As for the flashing...I don't really know about this, but you could try setting the contrast down to the lowest setting, or take the batteries out and pop them in again. That might help.
Well, as long as you take good care of your iD L (and invest in a sock for it, lots of people sell knitted socks for iPods and such, or regular old socks or pouches work just as well), it will not end up like mine.
Try not to aim to keep it in pristine condition, though; it's bound to suffer a bit of wear and tear over time. Good luck!