In fact, because they are generally decently paid and are in a regulated industry, they are probably much less likely to be a problem tenant (and bite.)  

Why is the practice of real estate so heavily regulated?

Most people do Not realize that when you form an LLC there is A LOT of rules, regulations, paperwork, procedures, etc. 

The boot camp is doing you no good service forcing you to purchase something you do not understand the liability and regulation around prior to ownership.  

Next, I'd say storage facilities, hardly any maintenance at all, especially if you rent a field to an RV owner.Then, probably boat docks, but you have regulations and maintenance and a few drunks.Then, parking lots, not a garage but just a lot with a self serve box, that can be great money.Nursing homes top my list of multi-family, a Hospice House has a lot of turn over.Then, multi-family, then office-warehouse, then other commercial REThen, single family but the appreciation is better and more marketable

Aren't there new Septic regulations in NH that he may need to get into?

Thus there are things like Regulation S to comply with to prevent flow back to domestic folks.  

I know nothing about Maryland tax liens and procedures.  

My question is though, what are the rules and regulation over here in San Diego specifically?

I also have zero knowledge of raising private money and any federal regulations that might apply.