What's the highest success percentage method to find a previous tenant's new address for this? 

Are there any common mistakes new investors make when working with brokers, lenders, or contractors?

Using your example, you sell Mon for your $155K and have a contract on a new home for $100K two weeks after this one sold.

I strongly would recommend finding a new tenant. 

That means new roof, HVAC, water heater, landscaping, painting, upkeep and so on.

It may be time to find a new PM. 

As a new investor, your best bet is to start small with an app like DealMachine or Propstream so you have direct control of your options.

Of that 50M, 25M was allocated for the construction of a new recreational faculty that has since been completed.

Would her income cover rent for a new home?

Historically in EBR, though, once the exemption is in place, it is unlikely to be removed unless the property is reassessed, there is a complaint, or some other action occurs to bring non-owner occupancy to light, such as buying a new primary residence in the parish.