If there's signs of other leaks in the home that don't have an obvious source then a plumber wouldn't be a bad idea.

The shower on one side leaks, previous owner put a sticker on it.

If it won't alter the rent to replace the flooring I advise you not replace the flooring.If you do replace flooring I would avoid laminate though on a rental, it looks nice for about 5 minutes then a tenant puts a giant gouge in it or the kitchen sink leaks and it buckles and it looks like hell.

Roof is 25 years old and 100% shot (but not leaking).

She mentioned that because the house was built in 1979 the foundation is prone to leaking water and it would be very difficult to prevent this from happening and subsequently destroying the finished basement.

Leaks: Look for water damage (water rings, bubbling paint / drywall), especially in rooms under bathrooms / kitchensConstruction type: Identify the common construction type in your target area and learn about it. 

I am looking for my new administrative assistant to be able to be able to access my social media accounts, phone calls, text messages, etc on an Iphone during office hours from my business phone number (which has also been my personal cell number for the past 5 years).

The challenge is that I did not know that it was a bad leak in the building that caused mold in one of the units and that I did not budget for, but I am working through it now.

Long story short: I thought I had a water leak when my bill spiked $1,000 for 2 months in a row.

I had something similiar with a tub spout that was slowly leaking into the walls for a month before catching it.