I've closed with several others and haven't had widely varying experiences so you should be just fine if you go with somebody besides these two. 

Varies widely by area so I can't say, but since I'm in California and you are in Pennsylvania, your numbers should be higher than mine, potentially much higher.

One reason I don't like it is the values can change from day to day with pretty wide swings. 

I also believe you will get a wide range of advice.

I just wanted to know if this is a widely held industry standard or something this particular investor brokered through a relationship with a local bank?

Just like any new endeavor you're going to want to go into eyes wide open and learn as much as you can beforehand.Please look up investing in Self Storage on the internet - lots of articles, videos, etc. 

My father recently sold his lot with a triple wide manufactured home on it, on Bainbridge, and I have a verbal contract with the buyers to get the manufactured home off the lot in 2 years.

I know it's quite a drive but the community I work with has a wide range of like minded amazing people.

I would keep the Community Bulletin board for community wide announcements -- like the pool hours or the parking lot is being resurfaced on this day.

Identify the zoning characteristics, political environment, and real estate market demand parameters for each parcel.With the wide variety of sites you delineate, there is a wide range of different development characteristics to research, design, entitle, and sell or build for each project.