So all things considered, the 5% and 6% returns don't sound terrible to me, especially given the costs of selling and where the market is in general (high prices and relatively high interest rates).The 1.5% on the other hand is pretty tough to swallow.

Also, if these aren't the way to go, what companies or agents would you recommend?

If you want to look for an investor focused brokerage or team in a brokerage I'd recommend looking for meetups in the local area for real estate investors or potentially other investor focused agents in the area, you can likely find both of these with bigger pockets (depending the location).

Can you see if these areas are worthwhile to invest, or recommend other surrounding areas?

They use a list of 10000 contacts (they did skip tracing, I ordered high equity/absentee owner list).

Its a gamble to go the permit route or not in Philly and absolutely matters the neighborhood/your neighbors as they are usually the folks that will call L&I on you OR if your property is near other construction sites where inspectors would be traveling to/from. 

There are a handful of commercial lenders that will lend on this but the rate will be sky high.

Replacing your cost of living will be almost impossible in most markets currently due to high prices and higher interest rates.

Thanks any CPAs you would recommend who are well aware of STR tax laws

I recommend you use an attorney to ensure the contract is clean and you are protected.