This topic has been discussed many times. Your points are similar to most non buyers. Basically, you can still build a good garage by spending a lot more time in the game. However, at high levels, you will still have problems against players with GS close to 9999 and drones/batteries advantage. There is no way around that as you cannot build up a large supplies of batteries playing one mission per day. You can still have fun playing and win maybe 50% of your matches.

I just played assault on my alt account and it is fine. No error.

Yes, RIDDLER_8. I am getting this too on chrome and firefox. I am playing juggernaut.