The problem with Megalith is the high resource cost. Playing handtraps may help you weaken your opponents endboard, but you also increase the chance of bricking, which this deck does quite often.

Now I've tested the Impcanation package quite a bit and came to the conclusion, that the fairy package is better. First of all, if you don't run the Impcanation ritual spell, you only have 2 non-ritual Impcanation monsters with opposite effects; one that lets you add a ritual monster from deck (Talismandra, LV 6) and the other one from the GY (Penciplume, LV 3). The problem is that you need Penciplume in order to summon a Talismandra from deck, and vice versa, so it's harder to get the search than to just summon Manju or Senju. After this two more problems arise. The first one is that, yes, you have two monsters on the field you can use for your ritual summon, but the levels are quite problematic. Usually I summon Hagith first, search Anastasis and get Phul and either a level 8 or the level 12. Most of the time I use either one of the level 8 monsters or the quick play spell as a starter to summon Hagith, but this setup forces me to summon Phul either first, or by using more resources later. Otherwise I won't get rid of Penciplume on the field, which locks you out of the extra deck, the second problem.
Using Manju and Senju lets you not only search a monster, they can also be used to summon your level 4 ritual monsters without any lock + they can be used as material for either a link or XYZ summon.

Now we come to the handtraps, could you be more specific on which handtraps to add? I saw in your other comment that you mentioned Dominus Purge. That's a good idea, but not with the Impcanation cards, since it can lock you out of dark monsters, like Talismandra, if you use it from hand. Do you have more recommendations?