Okay, you have some good reasons, but some of them will be taken the wrong way by non-vegans.
For instance, "it's not healthy". For this one, I'm going to bring up that a group of people went on a "meat only" diet for an entire year and in fact came out healthier than when they started. It may sound crazy to you, which I understand, but even if you don't believe that happened, which is again, understandable, there are people that do. Many people out there believe that eating meat is necessary for survival and can't understand how you can live without it. So I'd leave that part out at the very least, or try to instead bring up research saying being a vegan is at least more healthy than eating meat, rather than saying eating meat is straight-up bad for you.
For the "I don't think animals should be farmed in the conditions they are farmed", I agree halfway. Not all farms are run that way, though, so be sure to bring out a middle-ground position on that one. Perhaps it's just different in different areas, but I know that in the Midwest, most cattle are raised on open fields or fairly clean cattle farms, in a completely normal and healthy way, and you never see more than 20 or so in an acre, so they aren't crowded either. Then again, I know that some companies like to shove as many cattle into a square foot as possible and inject them with growth hormones, which is frankly disgusting, and those places are not very acceptable in anyone's book. So be sure to bring out both sides.
"It's better for the environment" is a confusing one for me. What part is better for the environment, letting the animals live, or removing meat processing plants? If it's the latter, I agree completely, and the former is.. well, let's just say there's a reason we go hunting. I don't know about cows, but I know that if we let all deer live, it will cause several problems in the ecosystem. This is because we've pretty much taken out all natural predators of deer for our own survival, so now if we let them all go, they will overpopulate, causing forests and fields to have fewer resources and giving natural predators more food, so then it goes the other way and the predators overpopulate and deer start to die out, and then since there are too few deer the predators start to die, then when there's more food in the forests the deer start populating again due to lack of predators, and it goes on from there. This is partially the humans' fault from back in the day when we needed to kill predators to survive, or wanted to for their pelts. Now we've thrown off the balance of the ecosystem and if we don't keep hunting deer, all sorts of bad will happen. So we continue to hunt, and there's no point in wasting what we've hunted, so we eat what we kill and try to use the rest in the same spirit as the Native Americans as best as possible.
Also, be sure to bring up "it's like asking why someone doesn't eat dogs, rabbit, etc.... like... ewe, why would I?", because it's fairly relatable to both sides, actually. I can see why someone would go vegan because they see cows and deer the same way they do their cats and dogs. They're both animals, and they both live, so why shouldn't they be protected? This one is completely understandable and relatable, so I'd be sure to leave it in.
I apologize if some of this sounds like it's trying to bash on you or go against what you believe, but truly I am only bringing up the anti-vegans' side of things so you will understand how they will react to your points and a few counter-points they will bring up. I will admit that the things I've written are for the most part things I believe, so that is how I know they are actual beliefs. I hope this helps you form your video in the way you are looking for, and I apologize on behalf of any non-vegans who take it the wrong way and start bashing you in the comments. As much as I don't get being vegan, I see no reason to do that to people that do.
As for how to form the video, it seems the other people responding have some good ideas.
Best of luck!