You don't need to wait, if the leader is inactive for 7 days then you can downvote them. Seniors can apply to become leaders first, then a day later, anbus can, after 10 days anyone can. But it does indeed cost ingots to impeach.

Only Seniors and ANBUS can downvote i believe? It cost 120 ingots. And if they don't have ingots, then unfortunately, the leader can not be changed.

Probably a wise idea to do. Don't take my word on it, I only did a quick google search and it popped up for 120. ;P