Can anyone confirm that you may keep Portfolio Margin (as opposed to Reg T margin) if you switch from Pro to Lite?
Pretty sure you can. Although if you have a large cash balance, one significant difference between the Pro vs. Lite is that Lite pays less interest for idle cash. Also, with Lite, you still pay for options, same as the Pro account. For my type of trading, it made sense to stay with Pro although if I was doing it over again, I'd probably go to TD.