As a reader, I tend to get annoyed by paragraphs that are too short. Granted, too short is still better than too long. But given the choice, I'd rather not see a bunch of 2 line paragraphs filling a page. Especially if the story is short overall. Flesh things out a bit. Add some detail, elaborate, expand. Thats the difference between saying what happened & telling a story.
Similar with sentences. Too many sentences that are too short make it feel like the writer is trying to force tension. Generate artificial drama. Fake intensity. Thing. If its done sparingly, it can be effective. But doing it too many times in one story just makes me roll my eyes. Like the author is unable of doing that on their own through normal writing so they rely on that as a trick.
With dialogue, like geraldg I don't want unnatural conversations that take place only to inform the reader of something (instead of informing the character). But in a 1st person story, it can be unavoidable. The reader can only experience what the narrator has experienced. And so the narrator needs to have other characters tell them certain things. In which case, I prefer it to be part of a dialogue than a monologue. Even bad dialogue is usually better than good monologue.
One other pet peeve of mine is excessive 'special' punctuation. Multiple exclamation marks and 7 dot ellipses come to mind immediately. I guess super drawn out moaned words would fall into this category too. And they often all appear together too. Like the other stuff, a bit is OK. For example, 'yes .... oohh GOD!' is perfectly fine by me. Just don't fill the sex bits with 'yeeeessssssssssssss . . . . . . . . . . . ooooooooooooooooooohhhhhhhhhhhhhhhhh GAAAAAAWWWWWWWWWWWWWWWWDD!!!!!!!!!!!!!!!' There are better ways to pad out the length of a sex scene, like actually describing whats happening. If you can't think of anything, go through the whole 'who, what, when, where, why, & how'. Not all of them are going to be relevant. But if it can be worked in, in a way that makes sense to the story? Go for it.