Everyone wants off market.You DO NOT want off-market deals.What you want are MOTIVATED Seller off-market deals!

Interesting, are you advertising to find motivated sellers? 

I've only dealt with residential at this point but am looking into self storage and on my search for commercial I stumbled upon a car dealership property where the owner is moving out of state and motivated to sell the property.

I suppose you could say the benefit is realized if rate comes down but nobody expects that near term and the early few years are going to be highest to a borrower who is motivated to pay off his mortgage, either AIO or fixed.If a borrower got a fixed and threw his money to principal every month (aside from emergency fund), even if he made that payment inefficiently (last day of month), it still is better than being super cash efficient at a higher rate.

Read books and listen to podcasts to supplement your knowledge and to use for better questions, more detailed, and then when you pair that with meetups and your motivation, you are on a great trajectory.

My question is, how do I reach owners who may be motivated sellers?

Even if their license is expired, the commission may be able to reach them and motivate them to send funds to you and communicate long enough to get control of your property back.Start looking for a new property manager.

Does anyone have advice for the following:Is it a good idea to explore whether to rent out multiple rooms in single-family residences for the purpose of acquiring adequate cash flow:Does BiggerPockets Pro provide a way to find demographical data on specific sources and motivated sellers?  

The big, pressing, motivator in my choosing to start with STR is my recent learning about the "STR Tax Loophole" and especially "bonus depreciation."

Quote from @Lisa Broderick: If you were an expert in a particular field, what would motivate you to mentor a stranger?