We will project the 'all under one umbrella' attitude in our web site and arrange deals with the local attractions for our guests.

Do I need to form an LLC or is just an umbrella policy adequate?  

Is there any way to work things so that we could secure 30 year mortgages on these properties and keep them under our S Corp umbrella?

Instead of an LLC if it is for asset protection I would suggest leaving it in your name so you don't risk the mortgage being called due and instead go with an umbrella policy to provide additional protection beyond what your property insurance covers. 

I have all of my personal insurance (car, home, umbrella) policies with them also.

Only thing was when I hit more than 4 I was required to remove the liability off each policy onto an umbrella policy but it's cheap. 216/year for 1 million.

Umbrella insurance, a quick explanation would be nice, from what I understand it's just a bigger coverage for your property.

Do you have an umbrella policy?

What makes it easier - good tenant selection, telling tenants what you expect, property maintenance and good relationships with skilled trades. 1 LLC, 1 business checking account, 1 umbrella policy, 1 spreadsheet, 1 pickup truck, 1 mobile phone and Cozy. 

As of now i carry a 4 Million dollar umbrella policy for liability.