It's important to note that day and swing trading is speculation, not investing. Unless one really knows what they're doing, don't attempt either in your 401k or IRA; stick with ETFs, mutual funds, and long term holds there. You can't really day trade in non-margin accounts anyway. If one really wants to day trade, have a separate account, and only put out money you can afford to lose.

I'd be curious to know what you've read on day trading. Not a day trader myself, but I did work in the industry. There's a lot of snake oil salesmen out there. But there's also some good books that give insight on how successful traders approach the market. From what I've read of you, bet you'd dig 'em.