So if you had 3 rentals with losses and 2 rentals with gains, the losses from the 3 rentals would offset the other 2 rentals and the rest of the loss would be carried forward to offset other passive activity losses in future years if applicable.

I had another person try to bargain me down to $1700/month, and said she was moving out of her dad's house and so needed room to store boxes in the extra bedrooms. 

Is your DSCR ratio greater than 1-meaning are you cash flowing (according to the lender's criteria of mortgage, property taxes and insurance (and HOA) if applicable).

I'm REALLY struggling with my applications through Apartments.com...which is TransUnion background check.

However, I see how one may struggle to change the email, since it may have important information stored or they've reached full capacity for making new emails. 

Perform the same task in each app to ensure a fair comparison.Load a property with pictures and details.Market that property.See what your marketing looks like from the public's perspective.Submit a fake application to see how easy the process is.Run a credit/screening report on yourself.Enter a maintenance request, assign a vendor, and attach a fake invoice.Enter charges to the tenant's ledger.Enter recurring charges and automatic late fees.Sign documents electronically.Run owner reports.After testing a few apps, one should clearly stand out.

Again, the BiggerPockets store has some books on this topic, or you can learn about it by watching podcasts, reading blogs, and interacting on the forum.

Cost segregation is a great tax strategy when applicable.

I already did her screening and verbally accepted her application, but my question is how to i move forward? 

Is your DSCR ratio greater than 1-meaning are you cash flowing (according to the lender's criteria of mortgage, property taxes and insurance (and HOA) if applicable).