I'd say so. The animatronic may not be the best killer but he's definitively good. I'm guessing those people saying he's a reskin have the huntress in mind. While they're kinda similar in that they both throw axes, they're very different. The huntress can throw hatchets with a very long range, she can carry multiples and reloads with lockers. The animatronic throws an axe with a lot more weight to it and a lot less reach, but when he's thrown the axe he moves faster. Also, the axe keeps stuck where it falls or on a survivor if it hits them and reveals their aura. He can recall his axe to his hand after a short cooldown. He can also use doors to teleport across the map.
His perks are alright I'd say. Nothing crazy but have potential for synergies and to have some fun. The DLC is cheaper since it's a 1 killer paragraph, so I'd say it's worth it if you're interested in him.
As for what chapter is best to buy first, I recommend Otzdarva's character info:
https://otzdarva.com/dbd/character-info. You have a section for killers and one for survivors. That should give you good orientation, but honestly if there's a character you that really catches your interest, I'd say check their power if they're a killer and if it seems something you'd enjoy just go for it.
Licensed DLCs need to be purchased (except Bill from L4D which is free by default), but all original characters can be unlocked using iridescent shards you get by playing and leveling up your account. In a few days the anniversary event will being and probably there will be sales for characters too, so it might be a good moment to unlock some characters for cheap :)
