This bug is not happening with or without Optifine for me. Sounds like something unique on your end. Are you using any mods which alter rendering?
Ummm, I don't think so...( also not using Optifine )
The textures for tinkers are also out of date in this pack...Is that it?
I don't use the whole pack or FTB, just the tinkers construct textures for my own mod pack.