I'm on Lane Kawaoka's e-mail list and I always think about striking out for something, but wondering if its worth it or if it can turn into a house of cards...

I left the free version of Stessa a couple years ago because of constant failed connection issues with my linked banks and credit cards.

Most firms in my market charge a transaction fee against the buyer agent's commission.

Some will just charge you the interest, some will charge interest + points, some will just want a % of the profit at sale/refinance. 

You can of course charge them for the extra days.

Additionally, I have an LLC established and currently hold a business credit card with a limit of $15,000, as well as two personal cards for $4,000 and 3500.I have before and after pictures of my fix and flip, if needed.Any advice or insights on potential funding sources or strategies would be greatly appreciated!

I generally dont like the idea of charging for more tenants.

Ironically, BP is now organizing content and CHARGING for access to that content, so they've gone full cycle. 

Granted this charge could be the one from 1996?

You can include a steep penalty per day that you charge if they fail to move out by the agreed-upon date or hold more money in escrow if you don’t trust them to move out.