IMO Actuarial at Melbourne is actually pretty cool so far, though it's only been a semester, so I don't have too much experience. I've found Accelerated Maths difficult only in that it takes a while for the concepts to sink in, mainly because everything is covered so fast. But you hit a point where everything sort of clicks and all the questions just become really logical and straightforward. There are 4 lectures a week and one 2-hour tute/computer lab class a week for Accelerated Maths 1. Apparently AM2 is pretty hard as well.. (FYI, I'm not the best at maths, got 43 in Methods and 42 in spesh)
As you probably know, actuarial stuff is mainly stats and probability, so if that's not your kettle of fish, maybe not actuarial... if you enjoy that kind of stuff, then you'll probably like the course in second/third year (we haven't done any of that stuff yet in first semester).
Commerce subjects aren't particularly hard, at least not from what I've done so far. Accounting is a matter of reading the notes and understanding all the jargon, Microeconomics is very logical and easy to grasp.
Again, just to clarify, I'm talking about UoM here, I assume Monash's course would be similar in a few respects at least? O.o