If your mom's IRA were to lend you money, and the IRS were to discover the prohibited transaction, you're mom's ENTIRE IRA, would be immediately and irrevocably distributed.

Companies like Fidelity prohibit real estate transactions because they don't make money on them.

A prohibited transaction for my 401k to invest in a business if I also provide services to that business.2.

By loaning to one another, your clear intent here is to evade this rule which creates a prohibited transaction.

It's a bit more expensive but not prohibitive. 

Hedging in the forward market is also usually cost prohibitive.

A lot of HOA's will prohibit &/or limit your ability to rent the property.

If you prohibit all dogs you're eliminating almost half of all prospects.We don't allow pets in apt. and allow certain dogs/pets in houses with conditions and deposits.

Still, for those properties on which there is open entry (no breaking and entering) and upon which I can document a record of apparent abandonment, there is no law that prohibits occupancy by a member of the public.

There is law prohibiting the actual straight up buying of a property, then reselling it.