Ooj
I don't see any reason to replace the kit bearings. I've raced 2 seasons with my F201 and haven't had any bearings go bad. I tore the car down at the beginning of this season and cleaned them out, but other than that, I have had no problems with them. As far as hopups go, the main thing is don't glue up the kit tires. The kit tires have very little grip and wear very fast. Get some Tamiya Type A or Pit Shimizu Hard compound tires. If you use the kit "nail" pistons, run Mugen 3000 weight silicone diff oil instead of standard shock oil. You can't get enough dampening with shock oil. Put some blue loctite on each diff screw when you assemble them and that's really about all that I would consider must do's. I would get a Tamiya High Torque Servo Saver rather than using the kit one, but the kit one will get you started.