Yep. I used to ALL THE TIME as a kid but now not as much, like if I feel something in there and don't have immediate access to a tissue you bet your butt I'm getting it out.
You have to clean your nose. It's gross to leave the yucky stuff in there. I use a tissue, then wash my hands. I did all the time as a kid. Can't say I always used a tissue.
Yep. I find that blowing my nose doesn't do anything. Possibly because of the structure of my nose (it's deformed on the inside). So I pick. Then sanitize the living crap out of my hands.
I find it interesting that we, as a species evolved to have our fingers always fit perfectly into our noses. Maybe we're supposed to do this? And society made it unacceptable? Either way, it's gross. If you do it, do so in private and wash your hands.