The tenants can clean up their act prior to close or the seller can evict them (though it might take 2 or 3 months) or work through code enforcement (slight danger but better than the current circumstance) to effect the change.  

If your heirs sold the property immediately after your passing, they'd effectively pay zero taxes.

Then someone can book on AirBnB for just Saturday night effectively loosing me at least a night in most cases.

You can always change them later if you find they are not effective or if you want something different.Ed

Prices will go down.Just consider that by refinancing your property, you are effectively buying into the house again at the current market price.

If you are positioned well going in and a swing comes, you can ride it out and it won't have any effect on you.

What are some good landlord friendly, easy to use, cost effective websites or apps to use to receive rents?

This triggers and exponential effect on your COC and ROI way beyond the % of commissions paid.

What would make this service efficient and effective for you?

We want to use VA loans when possible, how will this effect our business structure when acquiring new properties?