I am sorry, but it is kind of frustrating that these quests seem to be here to supply lower level PCs. Due to a bug (Let's not rant here) I used pretty much all my healing and most of my other stuff, and being denied these quests is kind of bad for someone looking to resupply after a harsh wipe like that.
Please remove these limits, if you can do every other quest unlimited times, why not these ones? low level people need supplies too!
Bats should not have a limit. Marching Dead should probably keep it.