This compares quite well to vanilla Throne Room, given that if you draw this without any other Action cards in your starting hand, you have the option of playing it as a Moat. Likewise, if you have two Lieges in your starting hand without any other Actions, you can still draw up to 4 cards even if you don't draw any additional Action cards.
Of course there is the downside of adding an Idle Hands to your deck, but as NoMoreFun pointed out, since it is gained to hand, they are easier to mop up (and could actually help more than hinder).
I reckon it's better at drawing your deck than TR, but worse at multiplying your payload. Ideally you'd play it on villages, which is totally different from normal TR. I changed it to cost $4 though, as then you can't open double.
I think where this can get dangerous early is less in playing a double Liege and throning two of the Idle Hands, and more the possibility of playing a double Liege, throning one IH, then throning a village, then playing the other two IHs normally. If you just throne two IHs, you end up playing 4 cards (L,L,IH,IH), drawing 4 cards (2 per throned IH), and virtually drawing 3 cards (including the IH junk you're stuck with), and spending 1 Action, for a net effect of
+3 Cards (one of which is junk, so really
+2 Cards), -1 Action, or a Smithy which adds a piece of junk. Adding the village (this can be any drawing village), you end up playing 6 cards (L,L,IH,v,IH,IH), drawing 6 cards (2IH, 2v, IH, IH), and virtually drawing 3 cards (IHs, all of which get played), spending 3 Actions (on the initial Liege and the last 2 IHs) and getting 4 Actions (2 per play of the villager) for a net effect of
+3 Cards,
+1 Action which is a triple Lab + village (or a double Lab + Lost City) that gives you no junk at all. Plus, as long as you collide the 2 Lieges in your hand, you get 2 more cards to find the village.
This still requires you to collide the 2 Lieges, and it still ultimately requires you to have 3 different cards, so I don't think it's broken, but it is potentially very strong. Given that you can't set up this combo on your opening anyway, my first thought was that it doesn't matter if you raise it from $3 to $4. But since most of the villages you would use to set this up (Mining, Worker's, Farming, etc.) cost $4, it actually does matter, as you can only buy 1 component in the opening (unless there is a plain Village). In Shelter games you could use a Necropolis, but drawing 2 fewer cards turns it into a regular LC (that requires 3 cards to execute). With a Fishing Village it is a LC that gives you +$2, which is not at all bad, especially early when your money density is below $1 (or not that far above it). Hamlet can work as well, as it can end up functioning as something between a Hunting Grounds (with no discarding), and a Forum + LC (if you discard 2), with the potential to throw in +Buys; the only weakness is that you don't get to sift the last 2 cards (unless you want to discard the IHs, in which case you are getting junked).