I lube the FEL and other stuff about every 10 hours as per manual. I do the same for the 2 or 3 zerks on the mower. Otherwise I don't have a set procedure but when thinking about your list, I do most of them in a roundabout way.
My tractor lives out doors under a tarp. So each time I pull the tarp off I look for mice and rats nests. (Had a dead and rotting mouse cooking on the engine a few weeks ago, took me a while to find the source of the awful odor.) I look at the lines and wires to make sure they aren't chewed up. I look at the site window for the hydro fluid every time before I crank it. Just a habit when pulling the tarp off. I do not check engine oil very often. Probably should, but its new and there's no evidence of leaks.
However, at the end of any given job or weekend I rinse the tractor off with the hose and occasionally wash it with some soap. As I do this I look over everything very well and this typically serves as a post work inspection. I think, for me, this is a very important part of maintainence. I get all the dust and mud off that can hold moisture against metal. I wash off the radiator screen, etc. My mower sits out in the elements so I always get the dirt, dust and grass off of it because even the dew can make it damp and lead to rust.
I need to check engine oil more often as well as checking the mower gear box.
In any case, it is hard to give a ratio of uptime vs downtime but I'd say at the end of a weekend of work, say 5-10 hours (I don't work the whole weekend!) I'll put in a good 45 minutes making sure everything is clean and in good shape. Not too bad, but is a new tractor.