Okay, just some random suggestions.
As for the dolls, to make them a little more menacing, don't use Animate Object, instead take fey and reskin them into dolls. Add immunities to level drain or whatever you feel is appropriate. Fey used correctly, even alone, can be scary for a second level party. Fey also come with grab-bags filled with fun extra effects like charms and illusions. The trick with the dolls is to give the party the feeling they're not a threat when they truly are. They also should never know if the dolls are truly dead. The dolls can stop moving/attacking but bid their time until they see a better opportunity - if they're getting pegged off.
Imagine this sight - the party thinks they defeated the last of the tiny buggers and starts breaking them in half, now there are twice as many SMALLER buggers chasing them slowly around the house (see below).
Almost forgot, a happy, creepy high-pitched childlike voice also creeps people out, use that if the dolls have to talk. Have them be interested in eating the characters if they need dialogue.
Next add a haunted house, for everything to take place in. Enough rooms that they can get lose or separated and so they have to fight off unseen forces (see below) the big bad (see below) or the dolls all by themselves.
Okay, scary low levelers, haunted house... time to add add unseen forces. Make doors slam shut on their own accord and be unable to easily open. Make walls move or rooms start to shift without any obvious cause. Twisting with the expectations goes a long way to messing with players. Add in subtle magical effects, rolling willsaves or alike, to have the players feel like they're losing their minds.
The big bad can be a monstrous horror or it can be a lunatic with magical powers. The best baddies in this case lie somewhere in the middle or BOTH. A giant lurking evil to avoid or face need only be something to distract the players from the mastermind which seeks to separate and corrupt them.
Side note: for extra fun, give any enemy level drain or ability drain. They may not hit hard or often but when they do the party will feel it. For a second level party, I recommend CON or STR drain but with a higher level group it is fun to through full level drain on them.