The law pretty clear in FL in regards to "selective enforcement" and arbitrary rules are unenforceable.  

To get motivated sellers, I cast a wide net but qualify them as they go through the funnel.

I choose to be selective with the HML company and choose wisely.

Choose wisely.Here's a blog post that delves into selecting a CPA.

My point is, maintenance can be more costly than you think and every beginning investor needs to have their eyes wide open that this can happen to them. 

I saw a very run down single wide on a very desirable piece of land.

The majority of the tenant pool do not consider the environment in selecting accommodations and it is therefor not business wise to spend capitol dollars to target a tiny portion of the market if it prices out the majority.

One idea if it is by a door is put open shelves so you have say a 10 deep shelf that is 24 inches wide.

IF you implement a no smoking policy for the building you will lose existing tenants at a uncontrolled able rate.Your best approach, assuming you do not want to drive out all the smokers with a no smoking policy is to selectively rent only to non smokers until all the smokers are gone and then implement a no smoking policy for the entire building. 

Seller financed 6-unit MFH.... selected "Other"