I sometimes which we had a modifier parameter for HP. Something like reputation which influences your vote weight. I know that reputation isn't the perfect parameter for this but I like the idea of active grinded accounts managed by real people having some sort of bonus

I can't really imagine a good way of implementing this, but I like the idea of giving real people a voice.

Additionally to come back on the million minnows, don't forget that if you are a minnow now and you keep grinding their vote weight will increase and be calculated in the background. For a whale to grind from 1M HP to 2M is going to take quite a while (or money). But a minnow growing from 1HP to 2 seems very doable