I would hit them immediately with a lease violation letter as prescribed by your lease and give them 10 days to remove the dogs or start paying pet rent and put down a deposit.  

I know i get letters every time I sell something and take back a mortgage/deed of trust.

They Seller Finance it with a balloon at 3 years, with the expectation you'll have established residency and be able to get a traditional mortgage. 

Lastly the Brokerage Disclosure to Buyer (BD-24) says this in bold capital letters further showing that this form is not a contract.THIS BROKERAGE DISCLOSURE TO BUYER IS NOT A CONTRACT.

We were planning $600/mo mortgage payment, $100/mo insurance & $100/mo taxes - balloon payment in 5 yrs.We are providing $5k to pay back taxes ($4k), back hoa ($125), pump septic & grease trap clean out ($225), survey ($600)  & our children are paying closing costs ($1500).Deal stalled as owner backed out on seller finance.Suggestions?

They provide the leads every month, you send letters and field the calls as they come in.

Should my wrap loan be for 30 years or should I include a balloon.

I sent the landlord a letter with 23 pictures using certified mail with return receipt. 

Always remember budgets always balloon as do time lines. 

I would look at historical and not the past five years as we were in a balloon. historical appreciation is around the same as inflation 2-3%.