It depends on the context and the specific rules or circumstances within the manhwa. Sometimes it might be allowed, but other times it could be prohibited.
Well, it might be a story about a man's unique way of keeping track of his grievances. The rocks could represent memories or a form of silent protest against those who have wronged him.
If it's her own painting and she doesn't mind, then you can. But if it's a work in progress or something she wants to keep pristine for a while, you probably shouldn't.
The answer is no. Touching raw manga without permission is not allowed. It might cause harm to the manga and could also be considered an infringement. It's important to respect the medium and its creators.
We can use simple stories. For example, tell them about a little bunny. Good touches are like the bunny's mom nuzzling it gently. Bad touches are like a fox trying to grab the bunny in a rough way. Then ask them how the bunny should feel and react.
Well, it depends. If the soft toys are yours or you have permission from the owner, then you can touch them. But if not, it's not polite to touch without asking.