Elven magic has "Return to Town" - this is a basic spell; there was also "Resurrection," but my Agrael couldn't master it. And in the "Ship" mission, "Return to Town" only worked for the nearest town, although there were games where this spell worked for any town – a list of your towns would appear, and you could choose. I think it was in Heroes 3 or 4. These same spells were also available in the Mage Guilds for humans, where you could hire Angels. However, Archangels can resurrect fallen creatures themselves, but after the battle, all the resurrected ones, as far as I remember, would go back to the afterlife.
No, no, "Return to Town," as well as various "Astral Gates" and "Summon Reinforcements" – these are a special group of spells; I don't know what they're called, something like "expeditionary" spells. You can get them in the Mage Guild by reaching a certain level, regardless of race (it seems you need level 12 for "Portal to Town"). In Heroes 3, I definitely remember that you could choose the town if you had the appropriate skills; in 4, you couldn't (teleportation, like in 5, only works for the nearest town).
"Resurrection" is a level 5 spell from the school of light. In principle, anyone can learn it (not just an elf) if they have the "Skilled Light Magic" skill.