leave the roots alone...
your not going to get root bound in a 5 gallon bucket with that plant... Flower it within the next week or two and your good... seseing some roots come out the bottom is normal... although most people will start out in a smaller pot and move it to bigger ones to keep roots from shooting straight down to quick...
I'd be more worried that the pot won't dry out decent with that big of a pot and small plant... I usually recommend fixing environment variables to make the pot be somewhat dry in 3-4 days... lots of ways to adjust that, bigger pot, smaller pot, big pot with more perlite, etc.... but you'll only know that once you start flowering...