So that is only 3 more than you could have rolled on a 1d10? split among 2 targets?
No. Read the last part where the surface area (on the bare stone floor) ticked a second time, which killed one enemy, and could have killed another if another attack hadn't already finished it. That is 3 + (2 enemies affected *(1d4)), or 5 to 11 more than I could have rolled on a single d10.
The fire surface ticks damage twice - once on impact, again at the start of the enemy turn, no saving throw. That's 2-8 more damage on a single target beyond whatever the 1d6 of the initial hit and 1d4 from the burning status do.
Plus, once we hit level 5 i'd assume the firebolt will deal 2d6 as opposed to 2d10 in 5e, while the burning damage will remain static most likely. But this is conjecture.
That assumption doesn't make sense. Why wouldn't it be 2d6 + 2d4, given that they changed 1d10 to 1d6 + 1d4? You have no grounds for assuming they won't change the Burning or surface damage to scale.
The Acid Splash effect is strong, but granted we don't have a help action yet to help land an attack yet. I don't see it as that game breaking.
Who uses their action to help others land an attack instead of attacking themselves? Especially because that needs to be carefully set up with proper positioning, and two PC's coordinating. I would be surprised if the Help action gets put in to the game for attacking.
So why not include it in a game where the book keeping is not an issue.
That's a strawman argument. The issue has nothing to do at all with bookkeeping and everything to do with balance.
Yes, the fighter may miss, reducing the damage, but so can the firebolt which then will do some mild fire damage.
It shouldn't do any damage at all. That's what missing is supposed to mean. I believe Melf's Acid Arrow is one of the few spells which can do some damage on a miss, and that expends a second-level slot. If you can find some infinite-usage cantrips with attack rolls which can miss and deal damage in the tabletop game that I missed, I'd be glad to hear about them.
