I had a lot of fun playing, but I agree with you, some things could be fleshed out.
I "finished" the game (30 REP) in 4 cycles (10 deliveries with complications), upgraded Flared Vents on the 2nd cycle and cruised my way to legend without too much difficulty. By the end I was sad I didn't get to try the other upgrades (specially the Skitch Hook).
The intersections definitely need more variations, perhaps a way to randomize the position of the entry/exit points alongside the columns/lane?
I like the idea of REP giving some kind of bonuses, a discount on bike upgrades would be nice too.
Also, maybe let chance decide if the delivery will have a complication or not, instead of letting the player chose.