Possibly. However we do know a few things too, so we can speculate. First we know that this is more than likely the cheapest creature for the Necro.
Sure. To my knowledge the Goblin Grunt is the only 4 point creature released so far. However the Darkfenne bat is an already existing good 5 point option for Necro since rot is a poison effect.
Each mage has their own variation, with differing stats. Basically the grunt that can be spammed at very little cost. Except unlike the Beastmaster's fox who has fast, this creature has essentially nothing (accept the possible soldier enhancement).
I would not discount psychic immune, and non-living as nothing. He is immune to a lot of stuff including poison.
There is the Acolyte who can regen the skele, but that means your using two spell points just to have a decent one spell point creature. The reason why this is an instant pass (accept for the possible later reveal of this becoming better with the soldiering) is that with what we have seen thus far there are far better options. Just go zombie. With a few extra mana you can have a zombie who can infect and turn others, not to mention be useful for shaggoth if they are about to die. Acolyte is still useful for the zombies giving them +1 melee making it easier to increase your horde.
I agree with everything here except for your point about the Shaggoth. The skeletons can be used as 5 mana growth tokens potentially after they have attacked for the round.
And don't get me started on this being a simple one bite snack for Kralathor. I couldn't even imagine the fear I would experience if an opponent brought him out with multiple skeles on the board.
That true. Very bad combination here.
As an aside realized one other thing looking back at the cards: Skeletal Sentry who looks like a Solider, is named for a type of soldier and even attacks with a real weapon does not count as a soldier while this dweeb with no armor who attacks with a leg bone and is generically named minion gets the Soldier subtype. WTH?