Assuming you do the due diligence and find a good property that cash flows and you monitor your property manager so that your tenants are happy, pay on time and your home is maintained, your golden. 

Alarms: Central Station monitored alarms will give credits5.

I monitor the L.A.

From my research so far Canary looks promising:https://canary.is/ Does anyone have experience with this cameras or other suggestions for outdoor monitoring of a front and back entrance and parking lot?

Myself, as well as many dozens of other investors continually monitor the market looking for any sort of deal (and this doesn't count the large number of rich parents willing to pay retail for a college home for their kids).

Why don't then the mortgage company/lenders have someone monitor these tax liens so they can bid when it is time of the auction?

The only thing that has worked for me is putting monitored, wireless alarm systems into each one of my houses. 

I don't see much value in monitoring these monthly.

It can also give you a better idea of the potential condition of the inside if there are pictures and the previous listings were semi-recent.Also, make sure to monitor the listing, depending on where it is in the foreclosure process (or how long its been since), they may grant access within a certain time frame of the auction.

As a multifamily appraiser, I am trying to think outside the box and come up with a service for multifamily owners (most likely targeting properties with 20 units or more).A current idea I have is to provide a "value monitoring system" that would initially provide a complete "as is" appraisal, then keep an owner informed of their property's position in the market on a quarterly, semi-annual or annual basis.