Here in the land of clay, I use a box blade on my DK45 to move earth (if that's what you want to call it - I have several well-developed expletives for it now....). That said, I have twisted my 8' Tuff-Line rake like a pretzel several times smoothing out the loose stuff. The Tuff Line tine frame is made of 4" box steel, but it is not sprung steel, like a York and the like. Use the draft control, and you should be fine.
I manage my 200 acres of ag land and 200 acres of woods my DK45. That said, I lease the ag lands my farmer neighbor, and maintain all of the roads, including grading, installing culverts, ditching, laying down cobble and gravel, etc. Now that I have an excavator with a dozer blade, I use the tractor less for that stuff. I mow unused pasture and whack the hedgerows when they get out of control too. I help him out by occassionally plowing (2-bottom), discing (10' transport), tedding, raking and baling (square kicker). Yes, a DK75 or 90 would be more suitable for ag, but I wouldn't be able to do the light stuff around the house with that kind of weight and size. Besides, it's too late!