Probably not. People usually have a lot of followers and viewers for their stories. Unless you are someone really important to him or he specifically checks who has viewed his story, it's highly unlikely he'll notice.
Most likely not. There could be hundreds or even thousands of people who view his stories, and one less viewer isn't something that would typically stand out. He'll probably be too busy creating new content or interacting with those who are more vocal about his stories.
Yes, some guys might notice. If a guy is interested in you or if he's used to you always viewing his stories, he may wonder why you haven't this time. It could make him think you're not as interested in him as before.
Honestly, it depends on various factors. If he is really into analyzing who views his stories and he has a relatively small number of regular viewers, then he may notice. But if he is just casually sharing stories and has a big audience, he probably won't give it a second thought. Also, if he is not that observant about such things in general, he will likely be oblivious to you not watching his stories anymore.