Thanks. I think this approach can be useful.
Personally I would completely avoid verses like John 20:28 and John 1:1. JWs have heard them many times and they have automatic responses to them. Don't try to prove that Jesus was god or go anywhere near the trinity dogma you will end up in a pointless battle of proof-texting.
You can allow them to assume that Jesus was created and subordinate to God and even that the NWT is a perfect translation. That is a lot of common ground to start from.
The OP builds a case for proving that the way JWs relate to Jesus is very different from the early church. That should give an honest JW cause for concern.