whatever the case H20
using the title God to adress the allmighty doesn't mean that Jesus is reffering to the God of Islam. It proves nothing really. Other then that semetic languages are semetic.
Using the same title doesn't mean your adressing the same person.
You talk of Isa but Isa is a different person then Jesus,
as is Allah a different person then God The Father in the bible.
No linguistic nitpicking will ever change this fact.