You dirty rat! :P

You don't have enough discard to make use of all the Megrim s and Liliana's Caress es. Take out 3x Megrim & 1x Liliana's Caress for something like Ravenous Rats . You'll get a lot more damage in and won't get stuck with those cards in your hand when you have no discarding.

Maybe also consider Nyxathid ?

how's this: I upped the amount of discard with Drainpipe Vermin , Nezumi Bone-Reader , Ravenous Rats , and Stronghold Rats

use Reassembling Skeleton in conjunction with Nezumi Bone-Reader and Mind Slash for the ability to keep making people discard if they decide to hold onto anything, or can't cast it due to mana shortage.

I would replace Reassembling Skeleton with the new M14 Tenacious Dead . It's cheaper on the mana. Maybe also take out the Megrim s for a Shrieking Affliction and another Liliana's Caress . Liliana's Caress is the just better than Megrim . The only reason you would run Megrim over it, would be to kill planeswalkers. As planeswalkers can't "lose life", and that's what Liliana's Caress does. Maybe sideboard Megrim for that. Though you do have Stronghold Rats to attack through to a planeswalker.

my thoughts behind having the Megrim s in the deck is that the more i have, the more likely I'm going to get them and start dealing damage with my discard effects.is that idea just not effective?

Also, I feel like having the Reassembling Skeleton is more effective in this deck because it serves as a handy discard that can go directly into play afterward (albeit, tapped) whereas the Tenacious Dead does cost less but it has to be in play in order to be used

Sure, that makes sense, but 4x Liliana's Caress es is more than enough I think, but I guess you'll find out after play testing. It's up to you and how you play it really.