Doug,
I would say with that list, the front blade will work just fine. I have done the same as your list with the front blade and it has served me well. One trick I have used in trying to level something, once you have it spread out, put the blade down and go backwards over what you are trying to level. The blade seems to "float and spread" better that way. If you are moving forward, it wants to dig in and cut, not spread.
I would say give it a try, and if you don't like the results, find a rear or mid blade, and sell the front one. I think you will find the front one will surprise you. One thing to keep in mind, the Cubs are heavy for their size. The will push a surprising amount, your main enemy will be traction. Depending on what OT you had, I would say a 123 would be a lot heavier than anything made after the mid 90's. I know with my 1450, me, winter gear, and chains, I am over 1000 lbs. You can push a lot with that kind of oomph......