I suspected you would get a lot more negatives than you hoped for when you started this thread. I know possums eat lots of ticks, and I appreciate that. Also, I think they're cute. I've seen TV shows where people keep them as pets -- I'm pretty sure my dogs, cat and house chicken would object to that.
I've had quite a few opossums show up on my property. None of the critters has ever bothered any of my birds, but I did freak out when I found one in a coop underneath a nest box. It was clearly not well and just looking for a safe place to hang out.
And, the one who crawled into the duck shelter -- who refused to leave the property for several days, even when encouraged to do so by my crazy terrier -- needed to find a new home.
I have relocated more than one possum -- most recently to a large, rural cemetery where it wouldn't bother many people and had plenty of places to hide from whoever and whatever.
I once thought I had been feeding a feral cat -- only to find out an errant opossum had been hanging out in my hay shed, taking advantage of free meals. I don't know which if us was more surprised!
So, count me as someone who likes the little marsupials and tries her best not to harm any. Now, if one becomes a chicken murderer, I will have to rethink my position.