I dont know how the voting bot works but do whatevers easiest, Im sure it can be an impossibe minefield to work out percentages etc. I woud make sure the membership list is full of silver and coin enthusiasts and make the reward votes equal.
The bot could throw out a random full vote once a week or month to a recognised member that has contributed the most to either a post or comment, maybe the bot could make a post of the week/month and we all vote and the winner gets a 100% vote on their vote comment so as a group we get a say in who gets a good reward for their efforts, runner up could get a 50% and so on.
If the bot needs recharging as a group we could excersise a slow week where we all reduce posts to give it chance to recharge and so on. Those in this for the long term will gest the get rewards whatever happens.
It`s easy enough for me to cut down the percentage to everyone when it starts dipping to low. I do like the idea of some sort of manual bonus votes and also having something to encouraged the community to vote for each other as well, these are great ideas.
I think tackling the membership list again is another issue as well.