You don't need an artificer to heal Warforged. They can also be repaired, or healed with healing magic (but healing spells only cure them 1/2 the amount). I haven't memorized all of the details yet, but iirc they do not heal naturally and can be repaired using various Craft skills. And I believe it doesn't even cost gold to repair them (but does require quite a bit of time, although if your group is sitting around waiting to heal naturally you probably have some time to spare anyway).
Artificer is just wierd, I don't really understand all of the mechanics yet. For example, if they "cast" bull's strength, it has to be on an object (including constructs), so the spell would work normally on a warforged but not a human. But you can get around that by casting bull strength on one of the human's items and then the item will give them the +4 strength.
Some of the warforged stuff can get tricky, like how they can't wear armor and need to enchant their skin to have magic armor, but they obviously needed some weaknessess to still be usable for a 1st level PC race.