But…..to be fair, he knew what the work entailed, he set the price with no counter from myself, and it went to plan.

I plan on managing these units myself.

Next year this time we plan on having at lease 1 more rental property and 1 flip property.

If you bank at a retail bank it's likely that you could pull a cashier's check to provide  certified funds.As to the wisdom of using other people's money (that you are solely responsible for) you'd better be comfortable with repayment even if things don't work out as planned.

Both were difficult and could have been avoided if we had had better planning.

For 15 years you manage to save up $20k per year and you have the missing $300k to pay $400k in cash.

I know that in single families in Cleveland Heights people have put in basement bedrooms with an egress window and they were on formal plans that were submitted to the city and approved. 

Reach out to your local land use planning and/or zoning department.

I plan on house hacking and was wondering if I should open a new bank account solely for the rental property transactions.

Hurricane prep and Evac plan for all properties.