Commissions ?? Trade all you want..... Don't forget you have to pay the piper.......
Yes if you're using a margin account.
If this is a cash account and you intend to use the proceeds from the sales from today, no.
You need to look up "Free Riding."
This is pure speculation. I hope it's not your whole pot.
Let's say I bought and sold stocks three times today. To avoid pattern day trading violation. Can I still buy a stock and sell it at a different day this week?