But if you, the landlord, aren't looking for it, you typically can't see it until the bricks start coming loose and real damage is done.

Instead of getting up on the toilet, turning around to face forward (putting 100% of body weight on one side of the toilet in the process), planting both feet on the seat, standing up, and squatting down (for #2 or #1), which will cause the bolts holding the toilet in place to come loose (our toilets are built to assume weight roughly evenly distributed on the seat).

Once in awhile I will work on the projects myself and for awhile I employed 2 people to cut the costs of subs, however after operating that way for about a year I found it was wiser to cut the two employees loose and operate with subs exclusively.

Vacancy: If a home falls apart and a lot goes empty for 23 months do you have the capital to buy and move a home so you don't loose a space. 

Assuming rents don't fall through the floor or I loose my job and can't find something else for several months I should be able to weather most storms but anything is possible...  

However, in our experience, while you may mitigate the cupping/buckling, you will not prevent it ... though you may prevent mould growth.My preferred floorings in bathrooms are (in order): {porcelain} tile (particularly with in-floor heat), linoleum (not to be confused with vinyl for which the term linoleum is frequently misused); or {loose-laid} vinyl sheet or vinyl plank.  

A year later another investor was loosing their duplex next door (divorce) and I picked it up for $82k. 

Add something similar to this to your lease:The Tenant covenants that he/she will not allow refuse, garbage or other loose or objectionable material to accumulate in or about the house and/or yard of the said properties and will at all times keep the said premises in clean and wholesome condition.At that point it becomes a fairly generic notice of breach, detailing section number, timeline to remedy, & consequences if non-compliant.

Is that recourse for me to get the good faith deposit back or is the risk I am taking loosing the deposit? 

Owning a 100 unit comes with a lot of benefits, but as others have said, you loose some control and have to answer to others.