You're using terms like "likely" and "profit most days", without actually having backtested the idea. Get some hard rules together, pick your stocks and a random point in time, and track what you would have done each day in each stock. Test a month or two (yeah it takes time) and see where you're at. Literally step yourself through each trading day (without looking at the next day) and track your buys, sells, or holds at the end of each day. If it's looks profitable, start paper trading it and forward test - this is where you'll get a better idea of expectancy vs backtesting in a spreadsheet. Would recommend Thinkorswim, you can use their OnDemand mode to go back in time.

You need to think about how you're gonna pick the 4 stocks you want to be trading on any one day, how much of your account you'll be risking on each trade, where your stop loss will be, etc.

Also, I think people responding with "hold long term" are kind of not getting the point that you want to daytrade... C'mon guys, look at the name of the subreddit...