It depends on who you're hiring but that seems fairly standard.  

If you building 2 , again depending on your lot size and projected finishes. 

GC's get paid off of the work, not a flat rate... but in your experience, would you say that window of rate is generally 10%-20% project depending, or more towards 15%-30%?

Depending on how close you are to Philadelphia you can really manage the property yourself as many Jersey neighborhoods are even closer to philly than some philly neighborhoods.

Experience depends on who you deal with - the cleaner the loan file and more organized your paperwork the smoother the process with any private lender.

That is often a matter of opinion and will depend on the attitude of your municipality.Most municipalities do not require neighborhood approval, but will offer the public opportunities to provide input which will be considered.

As a few have mentioned, the best way would be to call the listing agents directly, but depending on how much time you want to dedicate, setting and going on multiple appointments with different people could prove to be time-consuming. 

I think this totally depends on the investor and how many projects they are doing in a given year.

Valuation depends on your market = i.e. volume of STR supply and regulations. 

Depending on the class of property and types of tenants you have, they may not take lightly to you going in and blocking off their thermostats or installing electric heaters to bump the cost of heating into their electric bill.