The 2yr benchmark is for non-salary/non-guranteed income (there are different 'flavors' of salary...).While i don't do STR's, I think I asnwered your question above. 

Property owners should familiarize themselves with security deposit laws.Often a tenant may ask for a lesser deposit based upon their credit and rental histories or their personal financial situation, but the standard one month’s rent is a great benchmark for a deposit.

The lender that I chose for my HELOC was one of those who did not close or reduce any HELOCs during The Great Recession and did not close or reduce any to-date during The COVID Crisis; I know that history doesn’t dictate the future, but given that the Financial Crisis of ‘08-‘11 was the most recent and most severe benchmark to go off of, coupled with our current situation, I feel about as confident as I think a person can be in regards to that.

Is that a good benchmark? 

They will likely work with you more if you have volume I’m guessing smaller number of units is going to be a disadvantage so I would want to know what volume discounts look like going on so you have benchmarks to aim for!

It's still a nice benchmark to strive for, but increasingly hard to hit.

I've noticed now that rent prices have shot up drastically and a lot of deals work again due to the new benchmark for rents.

The benchmark mortgage rate has fallen since the end of March, when it reached the highest level since June of last year, and has remained under 3% for a month now.

As I'm unfamiliar with these costs, can some provide me a general benchmark on a per sf basis of what I should expect when bidding out (material and labor)?? 

I think I've seen 8% somewhere as a benchmark.