Assuming they have access to trusted and more affordable contractors and I don't have to manage the rehab (as much) it seems like a fair trade off. 

Make sure the contractors understand they are responsible to remove snow to access their work.More cutting, prepping, etc. work will typically be done indoors so make sure you hire a contractor who likes to be clean and won’t turn the entire interior into a personal workshop/storage shed.Figure extra $$$ for temp enclosures and heat if you wish to do exterior painting, masonry, etc.It’s darker later in the AM and earlier in the evening so make sure you have a lot of good, temporary lighting so you can maximize the amount of time your guys are working when they are actually onsite.Planon missing a few days here and there due to a “snow day” when guys can’t make it to work due to a snow storm.

Do you think vacationers would view a SFH that does not have beach access or a SFH that is located a mile from a beach as a negative versus a condo that is right on the beach?

I access my clients' books via my QBO Accountant profile.

Stop asking strangers on the internet for legal advice, hire an attorney, and put an end to this immediately.This should have been resolved the moment you discovered the unauthorized occupant.

I tell my sales reps that if the seller is really tough to deal with on the first phone call, then we usually want to pass on it, since if they are that tough just to ask some basic questions, imagine what they would be like when we need access, are negotiating a contract, or God forbid need to try to re-negotiate terms, i.e. ask for an extension, or every once in awhile a price reduction if the repairs a lot more than we originally thought. 

Your attorney would have to access your risk profile to suggest your structure. 

There are a few self-contained guides that you can access here: https://www.biggerpockets.com/guidesAlerts can be really helpful too: http://www.biggerpockets.com/alerts

This is a great forum with very knowledgeable members that will help to guide you in the right direction.I really like the alerts feature that can quickly guide you to current topics that may be of interest: http://www.biggerpockets.com/alertsThere are a few self-contained guides that you can access here: https://www.biggerpockets.com/guides

We'll be renting the main house out when we move and the house tenants will NOT have access to the detached garage.