I am neither a coffee or a tea drinking, I never acquired the taste for them. Although some teas smell marvelous.
My wife, who is a real tea drinking, does say that the black sesame tea is strong. At which I just chuckle.
I always add a little honey to my black sesame tea. I also never add three teaspoons for a single mug. I usually use one to two teaspoons; tending towards one and a half. Partly because after the seeds swell up, you have a lot of seeds to chew up and wash down.
As a note on the strength, I've noticed that the longer you boil the seeds the stronger they get.... don't forget the pot when it's boiling, because boy oh boy does it get black.
So:
Yes, you can eat the seeds, and Master Lin suggests you do.
For lighter tea, use fewer teas and don't over boil. I would think it is better to enjoy the experience and slowly work into the stronger tea.... if that's how it progresses for you. (sounds like good, better, best)
AS for staining the teeth, I haven't noticed anything. I suspect that for staining, it just as important What is causing the colouring as to oppose to How rich is the colour.
I hope that helps.
You are perfection.
Iam2