If it doesn't appraise for the asking amount, then basically I would have to bring the difference to the table, or walk from the deal, right?

Or is there another way to offer that still leaves negotiation on the table?

As Aaron mentioned, each agent is going to bring something different to the table and I would suggest being very honest with yourself when it comes to what you are good and bad at.

People grab a drink and have an open discussion, just inside the front doors at the high top tables.

So that is off the table. 

I am using a realtor for the expertise they bring to the table.  

I get calls all of the time from agents who have buyers that want to "Just measure the curtains" or "Wanted to see the Basement again to see if a pool table will fit" or "want to count how many energy efficient light bulbs they need to buy" or "To see if their camper will fit in the garage"The answer is always the same "I'm sorry we are unable to accommodate that request due to everything going on at this time".

After some discussion, we decided to structure our partnership 50/50, because we each feel the other brings as much value to the table as we do ourselves. 

If seller financing is on the table I would absolutely pursue that.

You could learn marketable skills that can put a roof over your head and food on your table.