I know a lender if you are in California. 

Even if you purchased your home at the very tip-top of the market before they dropped by 19%, if you would have simply paid your mortgage payments, mowed your yard, and stayed in the house for 6 years (you had to live somewhere during that time), you would have made money on your home...and that was the worst drop recorded.

Did you work with any real estate professionals (agents, lenders, etc.) that you'd recommend to others?

I understand residential financing, buying & selling, but I often hear there is more money to be made in commercial, but don't understand much.Should one start by finding a commercial lender first?

I would suggest you find a good local hard money lender.

I couldn't stick a capital gain tax on my mortgage company.

A lot of banks, credit lenders, and credit unions are offering ~5% on CD’s right now which is the best high yield I can find at the moment.

I’m thinking about luxury condos for short term rentals since I’d occasionally want to have a place I can use for myself.With mortgage rates so high and HOA fees for many of these buildings at around $1k a month, it seems like investing in a condo in Miami is more of a game of price speculation.

Double check with the original lender because some are allowing investors to assume the loan without having it be a primary residence. 

Where do you get the money to pay for the mortgage for those months it sits empty?