At this point, schedule a pre-move out walk through with them present acknowledging what they need to do to be sure to get their deposit back. 

NOI is a pre-tax calculation, which means all taxes are excluded from the formula.

Should I leave as is and cover it with a mesh cover for $2800 (really considering this), put a new liner in for 8k (not including new mechanics), or just fill it (don't know the cost on filling at this time)?

@Gustavo Tellez My first solo investment property was a SFH but before I got it renovated I had bought a duplex and ended up getting the duplex renovated first because I needed a place to live and was trying to move an existing tenant from one property into the other side of the duplex.

I had one done ~2 years ago and it was $1400, I think and that was a jump from pre-covid when it would only cost me maybe $1k.So, I think you can shop around and get a better price even if you live in a more expensive area.

The other two units that you yourself are not occupying have to cover mortgage payment based off of rent schedule.

Talk with your tax accountant.You sell it seller finance.  2 years later she calls you and said a capex item failed and she can’t cover.  

Additionally there is a $35 desk fee which covers the internet, office etc...Also every month I have to pay my own E&O insurance which is about $25.I wish you good luck in your new business!

we've been researching different kinds of financing and see hard money to cover the purchase price and a heloc for downpayment/reno costs as our best options.

There are lots of big $ pitfalls that you can encounter: second mortgage foreclosing, HOA foreclosing, other title issues, IRS liens, collapsed sewer pipes, burst water pipes from improper weatherization, to name a few.Start hereAbsolutely try to contact the borrower pre-foreclosure.