You should be able to do this with no problem. Damage eater itself has very high weight, but if the shield is clean, with just 12% eater, then you should be able to also imbue both Spell Channel and FC +1 with room to spare.
Also, this is one of those things where you can just try it, open the imbue menus, try to select SC and see what the gump says - you don't need to actually press the "imbue item" button in this case to just look. If it is available, and says you have > 0% chance of success then you can do it, if not, you can't. It may partially depend on your imbue skill level too as to what properties are even available, so if you're not 120 that may matter.