Make sure he is insured with workers comp (may be able to have exemption if only himself) check to make sure he is licensed as business and contractor. 

There's a reason we all signed up for do-not-callYou are right about Surveys, political calls and non-profits being exempt, but that is a slippery one. 

@Jordan Redar   no limit to how many you can buy,, however each state interprets the dodd frank in their own unique style.. and its the sellers responsibility to adhere to it not the buyer.1 to 4 units under federal law is relegated to the dodd frank.. under many state laws if they are non owner occ  then they are exempt.. some states they are not and when seller financing them you must have an LO put the paper work together for the seller.

Also, you need to be aware that the income coming from the financed portion of the property will be considered Unrelated Debt-Financed Income (UDFI) and will be subject to UBIT (unrelated business income tax).The alternative might be using self-directed Solo 401k Plan which is exempt from UBIT on leveraged real estate.

I've lived here long enough to be exempt from capital gains. 

@Manuel Savorelli If it is a buy and hold I would pay cash and then refinance under the Delayed Financing Exemption to recoup your funds. 

If I were in your position, I'd stay two full years so the house will qualify for the homestead exemption and you will avoid paying tax on your profits.  

If you like living in Oakland, you should utilize the most advantageous loophole in Oakland's rent control rules - the owner-occupant exemption for triplexes and duplexes.

However if I were to ever get divorced all the properties would still be subject to the jurisdiction of the divorce court to make a fair division of the property according to the various equity interests.So if I have $1 million in mortgages and go broke the property owned as tenants by the entireties with my wife ar exempt from collection attempts. 

I've noticed in multiple counties in Texas you can get a plat exemption when selling to someone using a loan via Texas VLB.