I was quoted $800 by a property manager years ago to replace a $150 garage door opener.  

If you see a lock box on the door to your rental (when you live downstairs), why wouldn't you call the tenant and question them?

no where near enough information for what you plan to do or where you are even at.

Have they mentioned what they might do or join in the future? 

This will enable them to manage a PM when they reach that level of doors.

I would close off the entrance except for your Italian restaurant, designated parking or valet. 

To answer your question, I am a passive investor and probably will stick to the doors I have until the opportunity presents itself (probably won't happen since I'm very casually looking for it.)As far as 1st lien HELOC and investing goes,  it seems advantageous to me to have the option to reinvest from the LOC if the opportunity falls on my lap as opposed to having debt/equity tied into a conventional loan.

Now you will have four streams of income vs one, and the tax benefits/depreciation, cash flow, appreciation & debt pay down will all exponentially increase your net worth by having four doors vs one! 

PS: not giving any of the check-in information until right before arrival helps avoid situations like this, where a new guest is beating on the door when someone else already has the right to be there until their check out time. 

We want to know exactly what interest rate we’ll pay on a mortgage, what the water bill will be, if the property next door is thinking of selling, and everything else that has even marginal relevance.