So, for the last few months she's submitting reports about breakers tripping (no pun intended), so we send an electrician out, and he finds a 20 plant grow with massive lights throughout the garage! 

There's always a city schill or two trying to trip you into a lawsuit. 

For example, 200 miles one way (guess) x $0.67 IRS mileage rate x 2 = $268 estimated vehicle cost per round trip, which is per guest stay.

Some variables conspire to trip you up Even if you know what you're doing.  

Or if they have clients who would LOVE to rent right next door saving the trip and trailering of horses.

For illustration purposes if a tenant or passerby trips and becomes  hurt because of a premises liability event, if you discriminate against a tenant or buyer, fail to pay your contractor for work that was performed or any of the many fact patterns that could lead to claim exposure presents itself do you really believe your identity is going to stop a plaintiffs attorney from filing a claim, lien etc?

They pop up here every few months, never to be seen again.3) Why aren't landlords tripping over each other to get these so-called wonderful tenants at these alleged higher than market rates?

I have a contemporaneous mileage log along w/ what was done each trip to go along with this.3) I am aware that for the IRS it is a red flag that I maintained a full time job over this period (a good amount of renovation work was done while working remotely waiting on jobs to finish).

Joshua tree, due to significantly higher elevation, does a little better in summer (but I have not been there in summer in my last 20 trips).  

I suggest you take a few trips out to Philly and explore the different neighborhoods to determine where in Philly you want to invest and what areas you want to avoid.