Do a Scaling exercise. 

So I feel no guilt in exercising such when one person is impeding upon, creating harm to, others as in this case.     

There are a few beliefs here I would like to invite you to challenge, in the very least it's a good thought exercise. 

Put your popcorn away because for now I am exercising the Lincoln Leadership method. 

@Jefferson Gan Generally speaking, a lease option does not transfer ownership until the option is exercised/expires.

The answer question 1, although they likely won't exercise it, they could technically trigger the due on sale clause and force a payoff if you transfer and question 2, Yes...you will have credit pulls regardless of the loan direction with few exceptions.

Continue studying along the road while exercising patience and persistence.

I'm sure some have timed things well but it's an exhausting exercise.

This benefits the buyer more, since depending on how it is written, it can lock in a future price and if the buyer would benefit from exercising the option he may, if the numbers run against him he can back out. 

There is an acceleration clause is most deed of trusts, that is, his mortgage document that calls for a full payment of a mortgage if the title is transferred in this manner, but people do it all the time and accept that is the mortgagee/lender ever exercises this clause then you'll just have to refinance the property and since you were paying the mortgage and have proof, you should have no difficulty in refinancing the property.