At my previous job they had just implemented retirement accounts a few months before I had left.

However hopefully they take good care of their medical implement and there are no issues.

I'm excited to begin investing some cash in buy and hold rental properties along with implementing the BRRR method. 

I wanted to get some input as to what features might be good to implement for this site. 

I called the the office and they informed me that it was a standard charge the property manager started implementing and that I shouldn’t bother cleaning when I move out because I will be charged regardless.

I would immediately implement a lease but month to month with rents at the current $38/sqft that he charges.

The credibility you are talking about is just you implementing your systems and maybe a letter stating rent is due when it is due and that late fees will always apply going forward.  

Both of those strategies if done properly will help you implement your plan of obtaining 3-4 more properties.   

You will learn very quickly by implementing those three resources in your daily routine. 

I've implemented the House Hacking strategy I learned about here at Bigger-Pockets which has allowed me to live for free in one of the units while the tenants pay the mortgage.