That said I wouldn't start destroying the building to save the bees, if the neighbor knows bees he might have an idea how to get the queen out then the rest should follow. or he might look and say they aren't honey bees. take him one , he'll know.
for the roof what if you just used rolled roofing and went up and laid it down over what's there. I know it isn't "right" but maybe just keeping the place from falling apart right now is the issue. If someone is going to live there they have some maintenance as part of the package. If you know someone enough maybe they could fix it up in exchange for free rent. but if not then I'd just try to keep the water from getting in. a re shingle isn't' a weekend job unless you are a roofer but that would be less mickey mouse than my rolled roofing idea.
we have a place in the interior of BC with similar issues , family owned, shared maintenence and time issues.. .. we also have woodpeckers. we tried to put up some fake bird houses over their holes with holes in about the same places thinking maybe they will move in there since it is blocking their entrance anyway.. for now we leave the woodpeckers because we had bigger issues with mud swallows and the woodpeckers keep the swallows away. yea they make more holes.. they are determined little creatures and so hard to discourage. But I dont' think they will multiply and live close together so they might do some limited amount of damage. I dont; think they like to live in close proximity with a lot of other woodpeckers. I don't know if you get barn swallows there but if they get going they will surround the entire place with nests all around the eves and make a lot more mess. they eat twice their weight in mosquitoes every day and crap about 5 times as much of course every time they enter they will crap on the side of the house. I'd take woody over those little guys. do you find most of the holes are about the same height from the ground?
It's a similar climate , it can get really windy and hot in summer and freezing in winter. nothing rusts much.
no electricity but maybe if you have a generator or something I wondered if you could use a spray gun with blopentine in one hand and a brush in the other and sort of make a day of spraying it down and don't worry about trying to dry it off , it'll suck the stuff up like a sponge anyway.
rats in the crawlspace might be another issue, it won't make it fun to go under and level and play with blocking , a dog might be more than willing to help with that at least if you visit for a weekend.
you might be able to mix calking and steel wool I think mice hate to chew through that and I wonder if a screen would help ventilate and keep the rats and mice from making a home of the crawl. mice can crawl through the prongs of a fork so I don't think you could keep them out entirely, if you can you are lucky.
I think you need to simplify what you do and just keep the weather out , the saggy issues and whatnot aren't going to change suddenly. go under and see if you can jack a little and put some blocks and dont; worry too much , it needs fixing but keeping the weather out is more urgent. If you wanted you could jack it higher and use the existing foundation and have a larger crawl. If you don't have rats in there you are lucky, they will make it stink. Id' take some good masks up there in case you have to move rats nests out. we use warfarin mouse poison, it helps. they go outside looking for water and mostly die when they get the water, outside. if you use that you can put it in a bucket with a hole in the side in case you bring a pet around, so they cant' get it.
a cheap thing you might do to discourage them is to leave a battery ghetto blaster there cranked up loud , it might encourage the wildlife to move out for a little while or at worst you drain some batteries.
if there is no power I doubt you have inspectors bugging you. just be careful since you probably also dont' have emergency services close either. Id' at least do a daily call to someone who would come help if you hurt yourself or fail to call in if you work on the roof or start crawling under there and jacking.
its a cool retreat I can see why you want to keep it. I would too.
you can use deer cams and things that will detect motion and take pictures, we do that.. but I wouldn't bolt the door too well. I'd empty it lock it and leave a note to whoever did break in to please close the door after and try not to damage your property. they won't see the note unless they break in, if they do there is nothing you can do but hope they at least close the door on their way out. if there is nothing there to steal maybe you could put a note outside that tells them there is nothing worth stealing inside here , or something? some thieves are out for booze and money but may not really get off on wrecking stuff needlessly. if they start squatting there then they are likely to also get trapped when you do visit. you could throw some fresh shell casings and stacks beer cans outside to help them think you are a redneck
