Thats a pretty wide range....the spec range is a guide  but i would say you will have a sweet spot between 120 -200 ......the lure weights you mention should work fine.......the heavier you go the more distance you should get and the more tired you will get over the day.......once you start going over 150g it starts getting harder work.....The spec is basically saying "chuck what you want!"to a certain degree.......sounds like a grunt stick.......does it have a soft tip for stickbaits? 

I fish regularly with a demon blood and it an all rounder, well not totally. I found that casting heavy poppers 150 grams very hard work and that is about the max i would go on that rod. I have tried 200grams but cannot get distance in fear of breaking the rod.  Prefered weights 80-120 work best in that rod. It work stickbaits in the 120gram range quite well.