Any suggestion on regulations or things to look out for will be appreciated! 

Yes, you probably could create a wraparound mortgage containing your existing mortgage within it.You might have to comply with the regulations of the Dodd-Frank Act.

There are already statutes and regulations regarding fraud and deception in real estate transactions.Educating people who want to be educated is fine, but if a governing body restricts the pool of ready and willing buyers, more properties will go to foreclosure and sit on the market longer.Real estate investors perform a vital function in every jurisdiction: putting properties back on the market, in good condition.Many of the properties they buy could never pass conventional lender's inspection because they typically require tens of thousands of dollars in repairs that most homeowners do not have or cannot do themselves.Additionally, many real estate investors near metropolitan centers can access almost an unlimited pool of funding to buy and remodel properties if the numbers work.From contract to close, the time can be in as little as 3-4 business days.The delay is mostly waiting on title companies.So when flippers mail letters and post cards to owners saying they can "close quick" and "all cash", that is a fact, not fraud.Of course, realtors will recommend you list your property – that's how they make money – so they are self-interested, which makes the report biased.Maybe next time you can have a "flipper" on you show for balanced reporting.The idea of anyone feeling "pressured" by getting a post card or flyer is ludicrous.If the homeowner doesn't want to sell, the solution is to throw them away.But the idea of "there ought to be a law" is equally ludicrous.If there are bad actors committing fraud, the answer is to enforce the laws already on the books.Out of all the properties posted for sale every 1st Tuesday of the month at the trustee's sale, a very large percentage never make it because they are bought by the very flippers you disparaged.If not for the real estate investing community, cities around the country would look much, much worse.My biggest complaint with your report is that you completely failed to get the rest of the story.Your editor needs address this."

I know that some is addressed in the regulations, though.

The pay or quit notice will assist the tenant in getting her handlers moving.If your tenant is lying, which is always a possibility, regarding the employment being temporary moving quickly will save you time and money in the event you end up having to evict as well.Issue the notice.In regards to accepting partial payment...read your state specific landlord tennat regulations. 

So the IRC regulates how the home is to be built then the IPMC regulates how the home is to be maintained.

There is ANOTHER petition circulating that will confiscate the permit of any property that doesn't generate enough Occupancy Tax in a year.https://www.tahoedailytribune.com/news/petition-seeks-to-tighten-south-lake-tahoe-vhr-regulations-maintain-current-cap/

Quick question for you: are there any regulations on using AirBnb with an FHA loan?

Obviously regulations in the US are much less complicated, taxes lower, laws much more landlord-friendly and profit margins higher than in Germany.

With any luck and a little discussion you might be able to find As for using Legal Zoom versus a local Attorney, I would recommend finding a competent local Real Estate Attorney as they know the in's and out's of the State and Local laws and regulations that apply to the area in which you are working.