My question again stems around using seller financing to allow them to receive a consistent monthly pay of X amount and delay/lower their tax bill in the short term instead of going through a lender to borrow 800k+ causing my mortgage to be significant part of our income roughly 40-50% of take home -  which we are approved for LOL.

If they show any aggression towards any person or animal, or if they are super wound-up or anxious, they are rejected.  

Are there specific lenders or servicers that are more likely to call these loans?

Are lenders generally ok volunteering for something like this? 

That would be for the deed, so use care not to trigger the acceleration clause with your lender.

Not all lenders are equal.

or market to Lenders for refi's ? 

Then if/when another good deal comes up, you can approach a lender and look at leveraging either of the properties in order to fund the down payment of the new property.

I have a robust team of mortgage lenders, title companies and RE attorneys.

I would get the same deal if I did another with the same lender.