Especially if you charged for applying, but even if you did not, I think you should rent at your advertised rate. 

It’s one particular property (house) that I’m very much interested in and I just applied for the deed ( 7/23/21).

I've seen a lot of people with less than $200,000 do some amazing things by having relatives or friends put temporary money like $50,000 or $100,000 into a buyer's bank account so the bank would approve the loan, but you need to put the money in a few months before you apply for the loan, or the banks will catch onto your scheme.The following image shows only one of the types of calculations you need to do to project your profits.

Since my spouse finances some of her properties herself, and the same applies to me - we would like to have a fair split in case of an unexpected life situation of divorce.

The lodging taxes apply.

Call around to lenders and just ask if they can beat it or should I actually fully apply to like 15-20 banks?

However, this presumption does not apply if the rent is current or the tenant has notified the landlord, in writing, of an intended absence; orWhen the last remaining tenant of a dwelling unit is deceased, personal property remains on the premises, rent is unpaid, at least 60 days have elapsed following the date of death, and the landlord has not been notified in writing of the existence of a probate estate or of the name and address of a personal representativeness.”So is it 30 days or 60?

There are a lot of rules and permits you might need to follow and apply for!

I do have some business credit cards I opened too, applied with my SS# since they largely go off your personal credit for the initial approval. 

You will apply for the mortgage loan as individuals on the same application.