Based solely on the points of the question, why would there be any doubt about if it is permissible? According to the Jewish tradition as found in the Torah concerning the confusing of language in connection with the story of the Tower of Babel in the book of Bereshit, Hebrew was the first language, that was used by all mankind. It is not the exclusive domain of Jews, but of all descendants of the first man, Adam.
The names of G-d which appear in the Torah are also not Jewish names, they are G-d's names. They are relevant to all nations, both Jews and non-Jews.
The benefit of Hebrew, particularly if you as an individual understand the meaning of the words, is that it is the Holy Tongue, לשון הקודש. That means that its usage is especially efficacious in communicating clearly and completely the intent of the speaker. This is because Hebrew actually relates to and reveals the inner essence and nature of existence like is explained in connection with Adam HaRishon naming all of G-d's creations in parshat Bereshit.
So the real point for you to ponder is, after careful consideration, do you believe that it is G-d's will that you serve Him as a Christian? Or is there a better path, a better choice for you?
From your comments and the details of your question, it sounds like that is where you are right now. But it also sounds like you are searching and questioning with sincerity. And in that area Jewish tradition teaches that for those who truly seek G-d, G-d will assist them and bless them.
May it be G-d's will, that if you choose to use Hebrew in your studies and your prayers, that you receive and comprehend G-d's unique message for you and that you have success in translating that message into good acts in your service to the Owner of us all.