Does having things like "LOL" and other stuff in the video title and / or description help or harm the video results?
It can... but it's a technicality... A lot of the "ranking on YouTube" advice, with people saying, "My video ranks on the first page in a search"... getting your videos to "rank" when you type in the name of the video isn't hard. Make the filename of the video, the filename of the thumbnail and the first keyword term all the same as the title on your video page and you're set. But here's where the technicality comes in... based on their advice, you have to type that title exactly for it to appear on the first page.
As an example, on my last video, titled, "Dogs vs Cats: Which is better?!"
If I type in Dogs vs Cats... the video cannot be found in the 25 page result limit on YouTube.
If I type in Dogs vs Cats Which is better… the video pops up on the third results page.
If I type in Dogs vs Cats: Which is better?!... the video appears on the first page of results.
Then, I took out the punctuation making it simply, “Dogs vs Cats Which is Better”
Typing the title exactly… Dogs vs Cats Which is Better… the video never made it higher than the second results page. (needless to say, I changed it back)
A persons search history on YouTube also seems to affect the results they see. Everyone in this thread could type in the same search and I doubt we’d all get the exact same results in the exact same order.
From what I've seen, YouTube's algorithm balances video popularity with keyword relevance to the search term and a viewers search history, which allows some videos to rank higher despite lower view counts.
With that being said, adding "LOL" or the like to your video adds an additional term, which, if someone searches for your video without adding the "LOL" means they likely won't find it as quickly, if at all. However, there are people who search specifically for "LOL" and "LMAO" videos so they would likely find it, and find it faster. It all depends on what you think people will be searching for when you title your video.