The problem with the modpack not working is because on Macs, FTB has some weird glitch where if the modpack is too large it won't extract it. The GL error is normal, it happens without any mods at all, and deleting the modpack doesn't help. Look at my previous post as to what to do about this... and as I stated, it takes freaking forever.
EDIT: To hell with this, I'm just downloading Millenaire off the internet. It's not worth copying everything over.
EDIT2: I got it to work! Just make sure to copy over the mod and config files, as those are the only ones that matter; for Millenaire, completely forget about it and download it from its official website instead.
P.S. The GL error is completely normal, it doesn't affect anything at all. However, it does tell you when you Minecraft just launched, and if you see that before any mods are loaded, then you know that it didn't install any.