Given the existence of Path to Exile and Swords to Plowshares this could easily cost as it only temporarily removes the creature.

Disagree. Pointing to the two most powerful removal spells in the game is not a good basis for determining the cost for your spells. If you go off the principle that "cantrips cost more than the original spell" you would find that this spell is not as strong a piece of removal as PtE or StP, true. But Camruth missed the fact that you could play this on your own creatures... perhaps a Mulldrifter... after you have already attacked and dealt 2 damage to your opponent.

Yeah, the delayed blinking ability is one I really like for the set (it's very flavorful for Immersturm), but I also want to be careful with how it can be abused. I'll leave it at 2W for right now.

I don't think Camruth was supporting/arguing the case for StP or PtE, more like saying that, as they exist and set a precedent. Also given cards like excommunicate, vengeance, etc. If this didn't have the cantrip then yeah would be a good cost, with the cantrip I agree that is probably better.

Do you think this design works better at the slot? If so, I could remove the cantrip. I'm just afraid it would be underutilized without replacing itself.

I'd certainly prefer the 3-mana cantrip.

I actually prefer the 3-mana cantrip myself. I think PtE was a mistake, and StP was from early on before they understood the strength of different abilities.
What I meant was, those cards have set a precedent (however much yo do or don't like it) and certain portions of the community expect anything similar to be on par or close to the power of those older cards.
Personally, I think this is fine.

I agree we shouldn't compare things to PtE without adding a mana, but a "1W: exile target attacking or blocking creature. Return it to the battlefield at..." without cantrip would be strictly worse than Turn to Mist, which I don't think anyone thought was ridiculously overpowered? Surely exiling temporarily is significantly less powerful than exiling permanently.

I'm not much of a judge at costing, but 1W cantrip doesn't sound overly aggressive (obviously playtesting may show it's more useful than I expect, but it seems a reasonable cost to start from). I agree the cantrip is a good idea, else this will often be card disadvantage.