All I could think about was how we had a house with an $800 mortgage and we could have rented that thing out for 3k and probably cleared about $1,900/month in positive cash flow after expenses.

Can I expense AND depreciate these?

I also require tenants to carry renters insurance - this protects YOU from expenses they get hit with.

Analyze properties based on rental income and expenses.

I understand that Heloc on investment properties can be expensive?  

I do the math to figure out these ratios for each applicant which is harder than you think sometimes with people working multiple gig type jobs with inconsistent income because then you also need their tax return to calculate factor their expenses in.

What is are the revenues and expenses? 

Are you factoring in capx, and other expenses?

However, the biggest maintenance expense, by far, is lawn care and snow removal.  

I just can't make the numbers make sense assuming a $0 capital expense for purchase/install.2.