Thank you for the suggestions! :)

1. The bot may vote the same person many times in a row

That's a great idea however, I want to implement the check for "last N hours" instead of last N voting rounds.

1. People may use tags that are completely unrelated to their post just to get upvotes

Proposed suggestions required a seperate thread to check the comments. And who will check the comments? It's hard to manage both technically and operational. There is an option for blacklisted users - bot operator should manually add abusive posts.

1. New users (low reputation) who produce quality content may not be rewarded

There is already a check for the "reputation". However your solution is diferent - I will think about it.