Replaced fill valve and supply line" and the charge came to 243.50 (this seems reasonable for call and the fix). 

Looking for a general contractor to get quotes on the following:-Replacing cast iron plumbing for PEX-Remodel bathroom-Replace cracked foundation in 2 car garage-Convert 2 car garage into Studio ADU (approx 340 sq ft)Any recommendations would be appreciated! 

Everything was gutted out and replaced.

The fact that REO properties are always AS-IS has nothing to do with the fact that many sellers of real estate are offering their property subject to inspections and negotiations on treatments, repairs, and replacement.   

I learned that I should have made sure the roof was replaced because I've had mulitple leaks since I bought it.

Bathroom hardward (TP and towel racks) - mount to a 1x4 plaque that is screwed to studs. you can pretty much hang on it without pulling out the hardware. i use entry level granite countertops - stain resistant, and should last a long time. i put LVP through the entire house, bathrooms and closets included. its water proof and scratch resistant. while the initial cost is more than carpet, you wont have to replace it as often. i use Sherwin-Williams Harmony line of paint, in a semi-gloss sheen. the semi-gloss is easier to wipe off for small marks, and the harmony line has deodorizers built in. for exterior door knobs, i use the smartkey knobs from kwikset. you can rekey a knob in a few minutes - no need to pay rekeying fees anymore. last tip - figure out which appliances your market typically provides. in my market, its not common to provide washers and dryers, so i dont. thats one less thing to have to repair. 4. i dont see an issue with the gas stove. to convert to electric you will need to have a 220V plug, which could be costly to install if not already there. 

Play close attention to the insurance policy as to what is covered after a potential occurrence, and replacement costs.

Anything you add or provide you are either going to have to maintain/replace or have bitter tenants on your hands when it breaks.

I said I wanted to speak to tenant B first but I am open to the idea of finding a suitable replacement roommates to assume the leases, as long as the roommates meet my original screening criteria.I spoke to tenant B and made the same offer, and tenant B was open to it. 

After 25 years, the flooring, paint, appliances and even plumbing fixtures likely all need replacing.