But the frequency of the problems keeps growing and growing.The owner holds on and holds on, looking for the absolute best market so he can unload what he has realized is not the best of investments for an absentee landlord.

Look for the lowest margin that you can get, and find out what type of index is tied to, the frequency of changes after the fixed period, and the caps at first adjustment and thereafter. 

I wonder what others use for their mailing frequency?

Don't forget that you CAN purchase a property for less than the prior one and use the gain toward improvements as long as it is drawn from the QI.I would argue that depending upon his frequency of trades, he could justify it if he regularly trades properties back and forth.

It depends, do you do any marketing where you already have the leads coming in, like through signs, mailings, etc.A lot of investors use craigslist to have their VA search for FSBO leads, I'm sure every town has it's own local advertisements; they can search there.Forms of payment can be through Paypal.The frequency of payment would be whatever you agree on; weekly, bi-weekly, you may be able to set up a payment arrangement based on your needs.Hope this helps.

I am not sure if the frequency with which he has shown me normal or not.

Many behave in a manner similar to a smoke or CO detector and emit a periodic warning "beep" when the battery begins to fail - the frequency may increase as the point of failure approaches.

By the more prevalent than anything else.In roughly the same frequency I see REI signs would be ones talking about buying junk cars, buying gold/jewelry, and "singles" websites.These are usually on polls like REI signs or in the ground like in the medians on highway on/off ramps.

(i.e. amount, frequency, for how long).

My preference is for multi family because of the reduced vacancy risk, but just know that multi's do tend to have a higher frequency of turnover (renters stay in houses longer), so expenses will be higher.