Unspecified colourants and preservatives are a big safety risk
Unfortunately E&C approved doesn't even mean something is safe,since it is in reality a loophole term that does allow food to contain BHA/BHT/ethoxyquin which are known to cause cancer without the manufacturer having to actually say so.
They definitely wouldn't be rabbit safe(cereals and honey would both be terrible for rabbits,even if safe for hamsters as long as the cereals are entirely specified).They aren't too healthy for hamsters either,and there are much better options on the market(and hamsters are omnivores not herbivores by the way).