-nowadays, they have a transaction coordinator, who keeps tracks of the deals' progress, which helps in closing deals. there is a charge for that if you decide to have someone else monitor the progress of the deal.

It seems like finding properties, finding honest contractors and even monitoring the rehab would be difficult from a distance.

You must monitor things. 

We have more control of the expenses and we monitor our propertys closely We know our tenants and know how they keep our property  We have 5 Duplexes right now.  

I have no idea why any decent investor would spend all the time and effort it takes to monitor and correctly work the velocity of money method to pay off the loan with the lowest interest rate when they could instead use that extra money and energy to create enormous wealth.

Biggest job 'permitted' by my town was the complete design, install & wiring/flow rate monitoring of complete fire sprinkler system for a 6 unit.

Even if "[m]ore tenants are likely to download movies that use a lamp to do something illegal", I am no more liable for one than the other.Now, if you are going to monitor your tenants network traffic and become aware of illegal activity, that changes the situation [never mind, that you would be breaching privacy law yourself].

(house is empty) Anyone using "smart lockboxes" like vaultlocks or supraekey that monitor and record access via smart phone?

Skype is another possibility, but I think 8x8 is more robust in terms of monitoring and integrating with your own existing solution.

Are you monitoring it?