When trying to analyse STR I try to use as many data sources as possible, AirDNA, Rabbu, Pricelabs and good old networking, ask around see what other investors are getting for their units. 

Echo this and add other sources like Zillow or Houzz...really great to get ideas, for free!

If you’re just looking for money to fund deals and you’re thinking the source could be IRA money then it shouldn’t make too much a difference to you whether the investor uses their personal funds or IRA funds.

Meet ups could be a good source too since you’re in a big market. 

- Good source to find reputable and experienced small multifamily builders once we firm up a specific market?

The data @Devin Conley posted is pretty solid from my experience (I do not know Devin nor how he sourced the data, just going by my own investing experience).  

Show Financial Stability- Proof of Income: Military pay provides a stable and reliable income source that banks value.- Creditworthiness: German banks assess your financial standing, so keeping accounts in good standing is critical.4.

What are the best sources or methods you use to accurately set rental rates in your area?

Akron is a very blue city and are not very landlord friendly - source of income protections, etc... 

I consider the two best sources is from other trusted contractors and other RE investors.