let's get your rom installed, and up and running first. themes and kernels are just add-ons that are nice to have - they're not necessities.
themes just change the look/appearance of your phone - they don't change the operations. a kernel is more important than the theme, and there are various ones to choose from. they are like a rom - each one runs differently on each individual phone. you just have to find the one that runs the best on your phone. the ones i recommend are: Raidzero, SlaYHer, Chevy, and p3.
but again, we first have to get the rom successfully installed and running.