Picking your ears in public is gross and should be avoided if possible.
However picking your ears in public is not the worst thing you can do but it's better to not do it when people are around.
However most people are not gonna really pay attention or care about you picking your ears, nose etc as long as you're not really close to them.
Picking your nose in public is considered rude.
However if you do need to pick your nose in public most people won't care that you do so as long as you don't wipe the boogers on something.
Just make sure you wipe your hands and wash your hands after picking your nose and put the boogers in a tissue.
Or better yet wait until you're not in public such as in a bathroom etc to pick your nose.
However it's also okay to wipe your nose in public and blow your nose in public as long as you're doing so in a tissue and you're washing your hands afterwards.
Just don't touch things in public that others will touch after you have had boogers on your fingers.
That is unsanitary and gross.