On the surface, I need to update/install fire and smoke detectors and CO2.

.- wall tiles- floor tiles

The final straw was going underneath the house: a water damaged subfloor which was there since the house was purchased was to replaced (reminded of it multiple times), it has not and tiling and flooring is down in the area the subfloor covers.

So I'm not living off what I earn in real estate but hope to someday not too far in the future.My handyman's take is, install the cheapest thing and be done with it.

I feel once everything is installed the mold will not come back but I would like any advice from people who have dealt with mold before. 

I'd look for the big ticket items first.. how's the roof, siding  or do you have to install a new HVAC?    

Cost to renovate $15K, payback about 2.5 years.The bath has tile.

I think I would install a toll gate!

I even removed the shower curtain temp as it was a small bathroom and I wanted the tile surround to show and make it feel bigger.

I've installed the kind that has a lock on the float so it can't go down unless the lever is pulled.