Would this be the ideal market, or are there other rental options we should explore? 

Talk to the seller, but options are to cancel the sale (and risk losing your deposit), renegotiate to lower the price to allow you to fix the problems or ask them to fix it. 

Be prepared that they will be promoting an optional mentorship program at the end.

Rates may still be high, but sometimes they’re more flexible with repayment options than a mortgage refi.Family Loan Structure: Since you have an existing interest-free loan from family, you could talk to them about restructuring or even adding onto it, if they’re open to it.

I was willing to pay but there isn't an option.

My goal is reviewing retirement options. 

If they do need financing, then speak with your lender about their new build financing options. 

@Roger CreekmoreMini splits sound like the best option from the cheap seats. 

I would check and see how many 1 bed and 2 bed options there are and what they are priced at because most folks will prefer the full place to themselves so rooming 2 people together could make getting bookings a bit more difficult (not always the case but something to consider)

Example: you can option to have a fireplace with two windows on either side.