What are you using the bike for? Sounds like you are using it more as a commuter bike than a Mountain bike. If the mirror you have requires being inserted than your 2 options are cutting the end of replacing the grips. I dont know anything about cell phone holders for bikes, but I would limit your distractions biking and talking on the phone shouldn't mix. As far as pedals go, pretty much go and get what ever ones you like I guess. I just use cheap plastic pedals on my get around town bike.