1. Is it appropriate to have a reception/picnic AFTEr the wedding back in our hometown at a local park (cabin w/ fireplace/outdoor games, etc) and invite everyone to that?
Yes I believe you should have a reception when you get home. Your wedding should be something you should celebrate.
2. DF wasnt ever married, so can we register and ONLY include the registry cards for people on his side of the family and friends?
Since we are doing a DW we are not going to register.
3. DO I walk down the aisle myself(second wedding, dad wont be there)?
It is up to you. Is there someone else you would like to walk down the aisle with?