Sh bair is a bad idea since you're going to end up with landing lag, and bair's landing lag is atrocious. Sh nair is very commonly used. For taller characters you can just press a immediately after inputting the jump, but with shorter characters you should input it as you start to drop from the peak of your jump or it will miss them. Unfortunately, I can't seem to get it into muscle memory myself, and keep accidentally nairing immediately after sh'ing, causing me to miss on most characters.
As for videos, unfortunately there's nothing, at least from what I've seen. I've been looking a bunch and asking friends who also play competitive Smash, and haven't found anything good. TL was already an unpopular character in Brawl, then after Link got buffed as much as he did and TL was nerfed, the few TL players we had went to Link. Then there are some people who mained TL in Brawl and were known for being good with him, but aren't getting SSB4, so that's not helping, either. The closest thing I can think of to what you're looking for for videos would be to watch the videos in this thread then read the critiques:
http://smashboards.com/threads/the-picto-box-toon-link-video-critique-thread.368737/#post-17907281
This video is very useful, even if I'm not sure it's really what you're looking for:
https://www.youtube.com/watch?v=GSU0FzdvHtE
