ROMs and Kernels
I usually stick to just flashing a ROM. Some come with good kernels and radios already in them. I would suggest using either thunderstick, BAMF, or cyanogenmod ROMs.
It's an old ROM, but I am currently running thunderstick bareback. I get great signal, battery life (after calibrating/removing battery stats), and my GPS works perfectly. It did remove all of the bloatware also.
You can install App Quarantine. I love this app.
It doesn't exactly uninstall certain apps, but it will keep them from running. Also once quarantined, it removes the apps from the app drawer. Just a nice way to save battery and clean up some space from apps you don't use.
Try flashing different ROMs and see what all you like.
If you insist on flashing different radios and kernels... as Watoy said, it can brick your phone if you're not careful.
Always make a backup and you should be fine!! Lol.