First off, it looks to be more than 3 weeks to go or I wouldn't have even suggested it.
What you do is go to the bend point on the plant stalk. Rub the stalk between your thumb and finger, breaking down the fibers a bit. This will make it easier to bend, but be careful and don't over force it. Tie a string to the cola near the top and tie it to the stake. Just don't snap it- the plant will be fine- I've done this 1000's of times. It's never too late to bend, it's about getting the room even so the light is working it's magic evenly across the tops of all the plants. What you did is fine, it looks a bit better than it was. And it's good practice for the next time.
Nope, I've never run screens, never had too. I'll stake some of the main stalks shortly but it's a Bubba Kush strain so it won't get too tall anyway. Tall strains I do I normally pinch back the main stalk a few days before flowering, to control height as the hormones disperse and then will stake as necessary.