Tried playing again, didn't run out of memory, but the book had a few missing pictures(Blank squares), and the items kept flashing between a white square and the item itself. It also happened to the items on the top of the inventory(The diamond chestplate). It didn't happen to my saplings, weirdly.
Sounds like something is corrupted. Try another pack and see how it runs. If that's okay, try creating a new world with SkyMyst. If there's a problem with that, then delete the SkyMyst folder and download the pack again.
Edit: FTB console says ###### GL ERROR #######, @ Post render, and 1281: Invalid value. All with [Client thread/ERROR] before them.
I'm not seeing any GL ERRORs either. That could be a sign that something is corrupted.
Edit2: I can't get a smeltery, my only idea is using the rock from chisel. But I don't know how to get clay...
There is clay generated in the world, just mine for awhile and you'll find it sooner or later.