The E10 is a vanity car. Its made to have pretty lugs and brake disc. However if there is any racing class where it might thrive, its VTA.
I think one of the biggest mistakes you made in your build was using the word NEW.
As far as powerplants go, most clubs are more strict about using motors than they are about bodies. Its best to just get a Havok 25.5 combo and dont look to change the class. As far as the battery goes thats up to the club. Really all of its up to the club. But if a club says that they go by official USVTA rules then usually they will follow them to the letter or they will declare any liberties allowed. ie- your battery.