Will All-In-One-SEO help you with YouTube videos? Yes, in a round about way if you load your videos onto a video website. Here you would be creating video posts and the same rules apply as if you were writing a regular written post.
Google and YouTube can send their spiders out to your website and use the information you put into All-In-One-SEO. This is no different than adding meta-data (title, keywords and description) to your YouTube page when you upload a video.
If you choose to go with another WordPress plugin, that’s fine just make sure you use some plugin.