Hi guys,
wanted to join the conversation.
I can speak of myself: Doing this (almost in the same way like OP) for years now, I never had any problems with either Amazon or Google (YT). Despite this, I have to say that I have "only" 800 videos in total on 2 channels.
My earnings are lower than OP's earnings, even though they are high quality.
Since the beginning I direct link as well but changed it a few months ago to redirect the traffic to a squeeze page (single opt-in) and promote the products afterwards with follow-ups. After that, income has trippled within a week.
The reason why it rose that much: I have only 5 niche areas where I've uploaded my product videos at. For each niche area I've created an own squeeze page with different background image and headline (which is about the niche topic).
So, there are 5 different links to 5 different squeeze pages and that's all. After every opt-in they get redirected as well.
Hope that helped a bit.
Kind regards!