How many signatures are required for a petition to be successful? Who decides whether the petition will be accepted or not?
You can see the limit on the site I believe its 7,500
A petition is a petition it is to show that a large amount of people (relatively 7500 people signing a petition for a coin in crypto is large) want some perticular action being taken.
Often petitions are not binding but they can persuade or make a party consider a certain action as that is what the public wants.
Ultimately Bithump will decide if they want to act on this, it isn't guarranteed that this petition will cause a listing but it is worth the effort.