Okay so you are serious. I’m not sure if you are familiar with tabletop rules or not.
Firebolt is 1D10 to align with the damage output of all the other classes. It’s an unlimited resource like say a sword or arrow (in this game). If you buff it and add DoT with surface effects, you are reducing the value of all the other classes. Firebolt also scales well as you level.
You should be able to have a familiar and animal companion. That’s a known issue that’s been stated. Animal abilities are fine as is. If they can’t keep up with your character, a change in tactics is in order.
Fighter is not a melee oriented class. They are actually the best archers. They are the best with weapons. Second Wind scales with levels albeit slower than what you suggest.
Rogues can hide again if they move away from line of sight.
Cure Wounds require touch because it heals more than Healing Word. That’s the whole point. There has to be some disadvantage otherwise why even have Healing Word?
