I've never seen an "All Other Perils" deductible restricted to percentage of the policy.  

Investment Info: Multi-family residential buy & hold investment located a 20-mile drive or 25-minute ferry ride from downtown Boston in the beach town of Hull, Massachusetts, also known as Nantasket Beach.Purchase price: $550,000 in 2016Cash invested: $137,500 from 1031 exchange (75% mortgage)A 14-unit property on a corner lot, and it includes an adjacent lot as well (10,000 sq ft total lot size, double the town median lot size), giving an exceptionally large patio, yard, parking areas front and back, and a storage shed.

He quoted a 20% fee for managing each successful booking and suggested we improve the staging of the house, which he would oversee for an additional 10% of the total staging costs.

I have an Oxford House in the Kansas City area.

It's exceptionally rare for rent to not be paid, especially to the point of having to file an eviction. 

It’s states …An occasional overnight guest is one who does not stay more than seven (7) days every six (6) months.Only persons 18 and older my be added to lease. 

Or, is it worth just getting an umbrella policy to cover all properties?   

It’s an excellent bookkeeping, accounting, and rent collection tool specifically designed for landlords and investors.

My question is...Should I give the property manager the EIN of an LLC that I already have and already use for a local LTR?

During your due diligence, you should connect with a mortgage broker, realtor, and contractors to gather enough information to make an informed decision.