My credit score is really good and I have around $450000 mortgage  on 2.75  rate for 18 more years.Thank youN.

You typically need 20% for the down payment and there are some credit score requirements as well. 

DSCR loans are based off of down payment, credit score and either actual or market rents so it helps to supercharge an investor's real estate goals and net worth.

The question is: Is there anyway to recover from this, find financing and move forward with the purchase despite 3 months of late payments on my credit report?

We have the LLC to build business credit and also get expenses out of our names as they are on credit cards.

What resources do I need to effectively screen tenants, how do I run their credit or criminal history?

The three pillars that qualify a DSCR loan, your credit score, loan to value, and the DSCR score ( gross rent / PITI(a)) - getting preapproved should be no problem as long as you have enough down payment, usually 20%, closing costs, and reserves. .

Event if it’s “bad” news / especially when it may scare others.

The down payment amount varies depending on the kind of loan and your financial status.Make sure your credit score is in excellent standing.

What is a general credit score I should have for my tenants to qualify for a rental property?