On the baiting subject, seems to me video evidence would be pretty damning. Next time you know they are there, simply video them and their bait site, make sure you get good footage. I'd advise talking to them too, but in the last few years there have been incidents where bad things happened, so probably better just to take the evidence you have to the warden. Make sure to get their license plates, etc.
Now, that said, SaskGuy might have the best idea. You could talk to your neighbors, and/or the guys leasing. Tell them you suspect that the reason they are attracted to your boundary lines are your efforts, and see if they're willing to collaborate. You can still have separate boundary lines of where you hunt, but you could then have 900+ XXX acres managed, which would benefit all of you. The whole baiting thing doesn't give you a good feeling about them though as far as being someone you want to collaborate with.