Many (most) individuals think a torque arm is necessary with rear hubs to keep the steel axle from rotating in the softer aluminum dropouts. I ran a 1000w rear system in aluminum dropouts for several years without a torque arm, but put one on my daughter's much less powerful front hub. There's nothing esoteric about kit installations IMO, but front end failures can be catastrophic, so if you end up with one, I wouldn't install on a carbon fork and aluminum only with a torque arm.