I'll tell you how to handle commentors and why you should conversate with them in your YouTube comment section. These commenters may be rude or critical. The best way to handle them is debate with them. Instead of getting upset and saying things that might make you look bad. Try and be more tactful or semi politically correct. Debating or even arguing with them while keeping it constructive will cause them to come back to your video and answer back. When they do that they are giving you more engagement on your video. Which boosts you up huge in YouTube search!