Emasher mod (whatever that is) adds some seriously junky blocks, one of which is Limestone (red sandstone is another). You can't make stairs with them, slabs, or anything besides the basic block and xxx Brick. For such a limited block, it takes up too much space under ground. I am probably missing some non-decorative use for this block, but if not, yuck.
Emasher Resource adds various ores and other resources to the game. All ores have retrogen, can be disabled, and their generation can be fully customized. The ores are for the most part, standard ores that you will find in most major mods. They might have fancy names, but they're all ore-dictionary-compatible with the ores, and ingots from other mods.
doesn't seem to add anything special really that you might need for Engineer's Toolbox. I'd just disable the mod, or turn off the generation of the junk blocks if you want to keep it enabled...
Ars Magica... all I can say is "wow what a mess". So. Many. Resources. I know this modpack isn't an example of a "real FTB" modpack to come, but I gotta say that I would never put Ars Magica in a tech-heavy modpack.
Ars Magica 2 is still a big WIP mod, but as always people kept complaining that it wasn't getting released, so Mithion released it, with the obvious result that alot of things are still useless, unbalanced or not working correctly...
Pam's... I want to make a bacon cheeseburger.
I hate mods like Pam's... it just adds sooo much, I've no idea where to begin with and it wasn't like I didn't got enough food without it. though it's helpful for those who like to play hard/hardcore and are in real need of early food.
so it's nice for those playing hard/hardcore, but for others... I don't know
Farlanders (I think that's right) and their huts+Ender Golems are way too common.
I don't like Farlanders... it doesn't add really interesting, just some mobs with similar trading systems as with villagers and some pretty ugly world gen in my opinion...