So, I'm meeting the tenant at 8:45 this morning to get the rent and deposit, and I'll do the work over the next 2 or 3 days.

Should I even sign the lease without the deposit?

I'll only do that if they pay me a non-refundable holding deposit equal to the security deposit.

We've already put money out of pocket for this project (ie. earnest money deposit on land offer, soil/perk test, paid builder to dig hole for perk test, etc).

The tenant has kept the place in great shape except some melted siding from a grill ($100-$300 repair)The tenant is a law graduate student and works at a firm, said all the lawyers at her firm said she has every right to move out and not pay rent.She also wants her full security deposit back as well.Should I just let her go and cut my losses, or should I deduct her security deposit and sue her for rent?

Before I rented to them it was full of college kids that trashed the place and wondered why I took the security deposit.

You'll need some of your money for marketing and earnest money deposits and inspections, etc.

Someone left a security deposit and we signed that she owes the first months rent on move-in date.

A little background: Hubby and I purchased an upper/lower duplex a few years back, remodeled majority of property, including decks, and allow dogs for a $25 per month pet charge plus $300 pet deposit. 2/1/1 units at $800/mo in Janesville, WI. 

Would Venmo deposit the money directly into their bank account?