I suppose that would work for the mouse, though it does rely on every thing else remaining in the same relative position: selecting a commander if a new one in the province has moved him down the list, for example.
I agree that keys are far better. I could probably do more with keys than I do, even manually.
For the blood example, yours would work I assume, though it would be simple just to pool blood slaves from the lab menu.
You could limit it to your hunting provinces, which would leave sacrifices and mages elsewhere their slaves, so that would be better than pooling. You'd still have issues sacrificing at the hunting provinces and with blood mages going out to battle from there. The real problem is that you've already built a lab at each province, in some cases just to make the micro less. I was imagining a macro that would transfer the slaves from the hunters to a scout in the province and set him to move to a nearby lab. Probably too much to ask. I might try one just to click 30 times to transfer slaves though.
That's my general problem with the macro solutions though. There isn't enough really rote repetition to justify it for me. Everything is just enough variation of what I did the turn before to break the macros. Of course, I don't play on 1000+ province maps, which may simplify things.
The real micro for me is in the slightly more complex but still not interesting tasks: A macro that found the x lowest research fire mages, assigned them hammers and had them forge lanterns would be heaven, along with another automatically assigned any new lanterns to researchers in castles somewhere.