You are giving a perfect damage output of the firebolt cantrip. Character's don't always set on fire, may not move thus not take fire damage, etc.
I have personally witnessed a Firebolt doing 13 damage onto two targets, because of the floor splash, and then one of them took another 1d4 from the floor effect. (I forgot how much it was.) If the other person hadn't been killed by something different, that'd be another 1d4. From a 1d10 cantrip. This is not a hypothetical, it's actually happening.
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So that is only 3 more than you could have rolled on a 1d10? split among 2 targets? 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.
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.
In terms of this being too DOS - no, I don't think it is - compared to DOS2 these environmental effects are massively toned down.
Plus, 5e does not include persistent effects so its easier to resolve and does not bog down combat. You can cast Fireball in a dress shop - all dresses on fire, the one the clerk is wearing - no, at least by RAW. Why? Because if you had to track burning clothes on each NPC that would halt the game to a standstill.
So why not include it in a game where the book keeping is not an issue.
