Assumable Mortgage Questions

[Michael R.]

I started out looking for investment properties that the owner will finance. I have found a few properties that the owner will allow an me to assume the mortgage, I will give a down payment, and they will owner finance the remaining balance. I have a few questions,
-Will the lender call the loan due? I have read a lot of conflicting info on this. What could I do to minimize some of my risk?
-Will this type of loan show up on my credit report?
- If I refi after 5 years will this affect my ability to get future loans?
Thanks for all the help as always