Let's say i have a topic with a poll and 80 votes but only 5 answers.

The topic will be on page 2-3 in few hours, because no one is posting. But in fact, the topic has a big potential since many ppl are interested in the poll and keep voting.

So maybe after like 5 votes the topic should be bumped.

think about

I don't think this is needed, with 50 topics per page shown the last post is 1 days, 14 hours ago.
The bump rule is 24 hours, so if you consistently bump it won't leave the page.