I think what the bank can offer later on would be 40 years loan with 30 year amortization, one can save 200-300 per month.

The laws are still evolving, so it's helpful to have a co-host that will keep up with the latest regulations, keep you in compliance, and help you to pivot your rental offerings as needed. 

Get offers from a few of them.

@Ryan Terrio what bank is offering that low rate for an ARM on a non-warrantable condo?

They offer ongoing coaching, deal review, and underwriting.

I can't help you on the agent part of things, but I do think making a list of all the steps you need to do to buy a property (find and agent, get prequalified for a loan, make x number of offers) and then put that list above anything else (regarding real estate) and try to start crossing one item off after another could help. 

They deliver what they offer. 

Would it be worth it to offer a gym membership as an amenity? 

Non/QM offers options but it does take a special loan program. 

-"commercial" local/regional tiny house builders will offer some financing option or another, find someone local in your price bracket and work with their financing-park models can be financed through dealers/(etc), and small ~400 or 600 sq ft singlewides, although getting spendy, perhaps, could look attractive once you factor in the negative of anything smaller being tough or impossible to conventionally loan down the line.