yes, with those 56l panniers you will be fine, and bungee cording tent etc to the rack will take some weight off the bags too (Ive always preferred sticking the tent there anyway, if its wet then all the better)
I ride a Tricross and find it handles well with two full rear panniers. Have never put a front rack on it, even if it has the mounting holes in the fork. What gearing setup do you have on yours (diff models have diff cranks and cassettes)?

not sure if you mentioned a handlebar bag, but they are very handy for snacks, keeping id and valuables, camera etc that is nice to be able to quickly grab without messing around with a rear pannier (map of course too) etc.