If my child is say 10 years old and hes quite new to rugby about to play in his first match......
Going up against a hardened team who have been playing since about age 5 is not really something I would like to try myself let alone ask a 10 year old kid.
Using padding doesn't sound like a bad idea - the use it in American Football, Taekqwondo, Karate competitions. Its not as daft idea as you think. It would be interesting to raise a team from age 5 using padding, gradually removing the padding as they approach age 6 and 7 and see how much more confiident and better tacklers they become compared to kids that start off with no padding. I wouldn't say this approach is the same as wrapping them in cotton wool would you?
But in the real world, you would get children coming in at age 6, 7, 8, 9 and in your example 10 years old. When do you remove the padding? Do they all remove it at the same time? Or after they've worn it after so long?
The social impact of coming in late and having to wear all that padding would be enough to stop anyone new wanting to play the game anyway. Not to mention the points people have made earlier about people becoming reckless when they feel "invulnerable" and end up getting themselves (and others) injured still. And also, it won't make a jot of difference to joint injuries like you mentioned earlier.
And again, you still haven't explained who would pick up the tab for these tackle suits?
It's a completely unrealistic idea.
You're an outsider looking in and trying to be innovative. That's great, and I encourage that. But you can't just assert your opinion and not back it up, and ignore other people's opinions. You said you wanted to talk to the experts. I'm not saying I am one, but I've got a degree in sport, I'm a teacher of children the age you describe, and have many years of coaching experience in numerous sports. There are others on this forum with even more experience than me, and more specific to the sport. You won't find anyone that thinks it's justifiable to spend over half a grand on tackle suits to teach kids to fall.
I think you just need to call this one a bad idea, accept why, and move on.