with a soil that has all the other recommend amendments, i'd go light on the rabbit manure, like one cup per cubic foot, and I like to mash it and mix it with the EWC prior to mixing it in the soil, seems to keep it thoroughly mixed, I've seen that if I don't mash it the roots don't seem to like the rabbit poo-pellets, they go around them, but if I mash them the whole friggin container is a rootball-mass, airpots rule, and using myco each transplant is a reason alone to transplant. Some people don't like to transplant very often but I have a denser root-mass when I work my way up to the bigger pots.
keep in mind, plants are sorta like people, you don't want to feed them just one item, they need a broad "diet" of nutrients. So on that note, rabbit manure can and will grow plants as a sole food-source, but you'll grow nicer plants with NO issues with micros and such using the ingredients that we all suggested (kelp meal, neem meal, crab meal, rock dusts, etc, etc)