"There have been some separation of the retaining wall at two of the joints causing some displacement of about an inch."

You can partner with a single investor in a joint venture structure (equity)3.

If finances are short (and I definitely can understand that), perhaps networking with more seasoned investors and doing a JV(joint venture) with them can help...or take on a mentor.

The loan/deed has myself and my mom on it.We won't be filing a joint return, obviously, so can the capital gain be split between us, each reporting $165k on our taxes and avoiding the $250k limit for capital gains taxes?

When I get a hit, I copy the mailing address,( I love out of town ones) and I check the deed - was it joint ownership, was there 'right of survivorship' etc - these notes help me to decide on which properties to chase,.  

I'd call around or ask around your local REIA for a recommendation... what our guy told us that it's cheaper to do a LLC if there will be multiple projects in the long run and less paperwork to do a contract/Joint Venture if you only plan only to do one deal...

Trying to figure out what is the 50% that the "brains" guy typically receives.b) Do we need to form an LLC + create a joint checking?

There is no need for knee jerk reaction. 

Those jambs were probably not tight at the joints or they had to manipulate them in the feild to make it square ect.

Joint Ventures: Exploring joint venture opportunities can be an excellent way to leverage other people's expertise and resources while learning and growing in the real estate industry.