I am deeply in love with cars, and so I was looking to see if making goals on a standard of cars rather then dollars or monthly income is an advisable way to set up goals.

When someone engages in a seller financing transaction, what are the standard stipulations? 

I did some searching, and found standard mail?  

Standard cash out is 6 months after your purchase for a refinance.

In a single family home rental the standard is the tenants responsibility to  keep the yard mowed by either buying a mower them self or hiring a service i would leave that up to them. you could include this service in the rent but most tenants dont see the value in lawn care included and the additional rent you would need to charge. 

The standard form has no place to add special provisions but I suppose I could ask the closing attorney if I could change/strike through and initial the form.

I am currently looking at another similar deal but I just backed out of it even though it met my previous "standards" and I got approved for the loan. 

We once put in an offer on a property and the seller showed the agreement to "her agent friend", who balked at our contract and said that it was illegal to not use the standard real estate form used by realtors.

Is there a standard length of time that a GC needs to guarantee his work for?

It's the industry standard for amortization schedules.