rear blade and box blade + TNT
tnt = Top and tilt = replacing top link with a hydraulic cylinder, and/or replacing one of the side links with a hydraulic cylinder. some folks replace both side links with a hydrualic cylinder.
would suggest at min. getting a TILT (replacing a side link with a hydraulic cylinder on the 3pt hitch) so you can adjust angle on the fly from seat of tractor. you have the longer straight runs but starting from home to going down hills, the ditch / angle most likely want steeper. and then i the turns, and then on the hill itself. you would most likely be constantly adjust the angle of rear blade/box blade. to get an angle that works better.
you are never going to solve your problems. till you get the water off the road and into the ditches. the one issue the 90 as you are going down hill. even if you put the water into a ditch. you are going to need larger rock in the ditch or your ditch will erode away. either make road slightly wider and extend into ditch with larger rock were water flows or get the water into the ditch and toss rock into the ditch. darn if you do, darn if you do not.
the road needs built up. more rock /dirt or something to get it up above the ditches.
the rear blade = helping with ditches and bring dirt/rock from ditches up into center of road due to how rear blades angle and move stuff from one side to other.
the box blade = better at filling in low spots, and physically moving high spots to those low spots. as in dealing with pot holes and ruts.
the land plane/grader scraper = more of a sifting device. it brings rock back up to the surface while allowing the dirt to fall down lower.
TNT = adjust stuff on the fly, you have to many different angles most likely wanted for rear blade, box blade, land plane. a side link of a TNT best bet.
make sure you have your "check chains", and "sway bar/chains" on the 3pt hitch. to help protect your 3pt hitch.
good chance you will be swapping between implements a good amount initially till you learn them. suggest telescopic lower lift arms, and/or pat's easy hitch, or quick attach for 3pt hitch. WARNING the quick attach (upside down U's) generally require you to cut off and re weld the connection points on 3pt hitch equipment. not always but many times.
WARNING. pending on 3pt hitch linkages. turn buckles to other types of adjust 3pt hitch, you may need a piece of wire or something around the large nut / turnbuckle to keep them from unscrewing and falling apart and loosing them some place.
google "forest roads" or "forestry roads" there is a handful of websites that generally cover a lot of the slopes, angles, crowns, ditch sizing, etc...