There is also a less-formal meetup group that meets around DC but they are all BP members.

And yes, a formal agreement needs to be made, especially with family.First, you need to speak to your tax adviser, as a member managed and manager managed LLC has different tax consequences. 

Just wanted to introduce myself a little more formally.

As I said, I  have been a "lurking" member of Bigger Pockets for a long time, and have even posted a few times, but decided to formally introduce myself to the community in the hopes of sharing and gaining some knowledge and insights.

I really do recommend getting some formal training/support.

Not too often would they send you some type of formal approval.  

Doesn't have to be major if it's family and friends, but you still want to be as formal as possible when it comes to these things so you don't end up losing friends later over something silly that could've been drafted into a contract in advance!

Doesnt have to be too formal - just something with your rough goals, strategy etc There was a good biggerpockets article or blog post on this the other day.

However, the most frustrating thing to all of this is that banks can put extra rules on top of what the formal guidelines state, and that's why we have so many different stories in my industry.  

The formal definition of price-to-rent ratio refers more to just knowing whether it's smarter to buy or rent a place to live in a certain area, but when used for rental properties, that's where it comes in.