Its funny, when I first came to DB, hibernation was one of the first things I played around with.
I dont think it has a lot of use for the leagues, cause as you rightly said any bot that comes accross it sleeping will just kill it while it sleeps, unless you can find some way of making enemy bots ignore you I.e. virus. I also played around with bots that hibernated when they were low on energy and bots with lots of energy would shoot energy particles towards them, to restart them.
Certainly some interesting ideas, but how usefull they are depends on what you want them to do and how you do it. But you certainly are resourcefull and seem to understand the DB language very well, so I look forward to seeing where this leads.