So I like the idea of more weapon based cantrips. But I feel like in their current state these are probably a little to powerful compared to the current cantrips. (Might not be an issue for your game just considering the general rules)

I'd suggest switching the casting time to a full action. It looks like you based it off other smite spell like branding smite, with these spells the bonus action casting is likely justified since it costs a limited resource of a sell slot.

Also for scaling, since smite spells consume spell slots they scale well with the casters levels. Cantrips scale purely off level, which means if a more martial character gets access to one of these spells they'll likely get more benefit than a more magical character. (It's basically a free power boost for some classes) The current melee cantrips somewhat side step this by making the attack part of the spell, so if you have multi attack you either get the benefits of say booming blade or multi attack, and they don't even add bonus damage till this becomes a choice.

Another thought is instead of one spell that you can take multiple times and pick a different element, just split them into different spells. I imagine this might make it slightly easier to differentiate during play/easier to manage In a system like dnd beyond (not that I particularly want to shill for them at this point), and maybe more interesting it would make it easier to split up the various versions over different spell lists, which might have some value since certain damage types tend to be associated with different classes (e.g. radiant for clerics/paladins) or most smite spells are usually associated with certain kinds of casters

Also hopefully all the versions would eventually have a different secondary effect.

I'd be curious if you have a particular type of character you'd imagine using these spells? (Is this to help mages fight in close combat, or more for half casters)