I play, or played, a mash up of medic to frag, solider to be lazy, or engi to do the obj or be a pain. I was never great at any but I feel like I was decent if I tried. I feel like all the classes are balanced on a server the size of ETL1 and on the Legacy mod, more or less, given we have all the skill levels maxed other than medic4. While I don't play right now I know settings haven't really changed. Nades is fine imo, as is a soldiers smg.
Maps, spawn times and all that jizz can be changed but there's a fine line to balance it all.
If we increase say Venice spawn times by 2-6 seconds for Axis like suggested, how would that effect them spawning at that first spawn and defending it? They would be crippled imo. if I play engi I sometimes I don't have time to build and plant mines as Axis before the tank is a the gate. It's the bank area that is a slog. How do I fix that? I don't know. Give Allies a tunnel to blow in to the bank as well, something that takes Axis away from sitting around the courtyard Maps are most balanced when there isn't 1 or 2 attack points in an open space that bottleneck in to 1.
And, as suggested, Deli spawn times. Axis spawn too quick then there's no point, but spawn to slow then they can't defend either the flag or the button. Believe me we have tried most combinations of spawn times on the popular maps and settled on what works, the majority of the time. The majority of time being the key phrase here. You can cap the flag in the first spawn allies have and hold it but it could still be a long slog to both tap the button and hold the truck.
All is just my opinion of course and no reflection to what is what.