Best Wallet Practices

Hi all, I just got an electrum server running on my node and set up a mobile electrum wallet through it. I've got a few questions about best wallet practices and mixing with Wasabi before sending BTC to hot wallets and cold storage.

I plan to for my coins to go from P2P - Wasabi Wallet & Mix - Electrum / Cold Storage. Questions Follow:

1. When I'm buying from p2p markets if I buy from the same seller multiple times; should I use different addresses each time, or one per seller?
2. When I mix coins in my Wasabi wallet; do they get mixed and returned to the same address, or are they sent to a new address in Wasabi?
3. Are there any privacy concerns when moving mixed coins from Wasabi to a hot / hardware wallet?

Thanks for the assist.