Asides from paying the difference on close date, what strategies can we do to not let this deal fall through?  

The limitation is that if I want the exemption, I have to agree not to rent out the place for 12 months after the date of completion.The only loophole is that if the construction cost is going to be less than 30k, no licensed is needed so no need to apply for the exemption hence no 12 months limitations.

A custodian can certainly have a meaningful impact on fees, the types of investments allowed, and the speed with which you can transact.

Sidewalks should have no weeds or grass growing in any cracks.HOUSEKEEPING INSPECTIONSWhen the Landlord or agent visits the unit or conducts a maintenance inspection, the Landlord will schedule a follow-up housekeeping inspection if there are concerns that these minimum standards are not being met.Landlord will advise Tenant of the specific correction(s) required to establish compliance, and also advise the date that the dwelling will be re-inspected for corrections.

Current lease term (expiration date, month-to-month)7.

We always do 1 year from the date of move-in and then rolls into month to month. 

I set a date for them to pay their dog deposit by, and it's about to be due, but they haven't paid it. 

You can give proper notice that you are not going to renew in any way (term or month to month) and they should vacate on X date. 

The notice must clearly state the date that the tenancy will end.

There are groups that have track records dating back to the 80s and 90s, with billions of assets under management, but never market themselves.