@MoominKitty please don't do that with the cats licking spoon and ice cream, their mouths are so heavily laden with bacteria and you are genuinely putting your self at risk of serious infection (cat bites always need treating with antibiotics for this reason) I assume you'll say you've come to no harm so far, but it really isn't worth the risk.
As for the main thread. I always wash my hands, appalled that so many don't - think about everything you touch in a bathroom and if the person before hasn't washed their hands but has had a poo.... Eurgh. No thanks.
I do pick my nose. Quite obsessively. I think it's a symptom of my anxiety conditon. I also obsessively pick scabs.
I am quite obsessive about hand washing though, I don't trust handgel to do the job properly and will wash my hands and then apply hand gel.
I don't touch public door handles (especially not in public loos) or ATM or elevator buttons, I have a clean tissue to hand as a barrier or pull my sleeve down.
Obviously I do touch stuff in public, it's just those specific things give me the heebie jeebies.
I've also been known to pee in a large kitchen receptacle, when I've been too lazy or too busy to go upstairs for a wee. It gets boiled and spritzed with disinfectant afterwards.
I'm minging, I know I've got a cheek to comment on others disgusting habits.