However, obtaining the permission of heirs is probably a logistical nightmare that makes it cost prohibitive.

Almost all residential loans will have either a due on sale or a clause that prohibits assignment.

But as stated, any contract that doe not specifically prohibit assignment, is assignable. 

Custodians tend to take a more conservative approach when reviewing alternative assets for investment, as they want to avoid the custody of any assets that may be involved in prohibited transactions.

Tried having tenants take care of it together but one tenant dominates and snarks at the other for too many flushes etc.My bill is almost $400 for 3 months.Water meters 5k and new water line prohibitive. ???

Some banks sell homes and require you to agree to a clause that prohibits you from re-selling the house for 90 days).

many of the 55 plus hoa 'a prohibit renting out altogether.

Not sure if they work in your areas, but I have homes all over Alabama.They have a few rules, like NO trampolines and they prohibit certain types of big dogs.  

Fees for garbage pickup may be included in the owners property taxes; thus, you may be paying for this.In addition, one reason the current landlord may be paying the water/sewer charges on this duplex is that there may be only one meter for both sides (not unusual) and it may be cost prohibitive to run a second meter.   

You will want to educate yourself on the rules, as the IRS is very strict about certain things such as prohibited people and prohibited transactions.