Look how many religions (technically at least) actually follow the same god just in different ways, there should be no problem with taking bits and pieces from any number of religions and grafting them onto your own beliefs.
I still go to church some sundays even though my beliefs have moved way beyond that, I don't see any real problem theologically with that.
In my view (and that of every version of the bible you can dig up) Free will is the most important thing God gave to us, just following a religion like a sheep is rejecting that gift, which would you be more pissed off with, someone making good use of a gift you gave them or stashing it in a box under the stairs?

No Religion has Exclusive rights to the truth.