1. Yes
2. Yes
3. Yes, there are three different colors (green, yellow, red) indicate your bid situation.
4. Some people like to scare an opponent bidder a bit, like me, I bid 2-3 times in one round to let other bidders know that I have a ton of token.
5. As some people come late for that particular player, he/she thought the previous bidder has made a bid and left the scene.