After having the contract signed, I’d put it up on the MLS and market it there for full value and only accept cash offers with a non-refundable deposit; instead of selling it off market to another investor who will give me nowhere near full value.

For example, does Buyer 1 also have to match our 30 day close in order to honor the contingency? 

This is cutting it too close to comfort with the time needed for bank transfers from venmo or even a check deposit to go through.

I realize I can get great online with the big guys, but no way I'm giving my operations account and the majority of my deposits to a bank that doesn't lend to me (and I've had way more luck with local banks than the big banks since most of my deals tend to have some hair on them)

My present company doesn't charge for that, but then charges me to inspect the unit to determine if the deposit should be returned and if now how much is kept.

Nevertheless, you owe it to yourself and your business to keep looking until you find a good match.

Typically the way it works is either party can make an offer to the other and the second person can match the price plus $100 and the first party then must sell to the second. 

We did take a deposit for the two dogs and charged $125 pet rent each month. 

I understand that any future deposits into the solo 401k must come from the LLC and not from me personally.Thanks in advance.

First thought was to- My party keeps security deposit.