"... meaning speakers are aware of the manipulation of informal language in regards to their liking."
This is a focus/awareness issue, because you (presumably) weren't aware when you were writing this sentence that it would be read/interpreted strangely. Or if you were, you ignored it. When you're writing, you have to write like you're yourself, but you have to read like you're someone else who isn't already inside of your mind. When you get in the habit of "seeing your writing from the outside", you start to realise that some of your words can have double meanings and your sentence constructions are unclear in a way that either, they can't figure out a meaning, or they can get more than one meaning. If you find yourself thinking "they'll know what I mean" -- they probably won't, or you should assume that they won't. I was once recommended that I should write philosophy essays as if the examiner was "mean, dumb, and tired". Assume they hate you and will look for an excuse to interpret your language in a way that isn't clear.
I'll give an example..
"I like precise language."
This is a good sentence. There is only one meaning to this sentence.
"I like language to be precise".
This isn't as good. Can you find the two meanings here? Try to figure it out before you open the spoiler.
Spoiler
This could either mean "I like precise language" or it could mean "If I'm speaking precisely, the thing that I like is language". As in, "To be precise, I like language". Obviously the first interpretation is better, and you probably wouldn't take the second interpretation unless it was "I like language, to be precise", but what if the rest of the essay was missing commas in important places and stuff like that? The point is, if there's even an OPPORTUNITY for your assessor to be unsure, then you should be more clear. For example, I thought that "speakers" in your sentence were talking about a particular audience made up of speakers, until I read aqple's interpretation which is different. See - two people, two different interpretations, because the construction of your sentence was in some way ambiguous.
I was going to deconstruct all three of your sentences but really it all comes down to focus and being critical of your own writing within the moment.
Tips:
Stay focussed
Assume your assessor is horrible and mean
Write as if you were talking to a really, really smart person in Year 6. They have a solid vocabulary so they'll understand the words you use, but they are only used to reading clear writing. Unclear writing won't make sense to them because they aren't used to figuring it out.
Read your own writing out loud a week after writing it, or even a day later. Just leave some time between the reading and writing. No one ever takes this advice because they're stupid, so at least read your own writing inside of your own head. Once you can read the whole thing and it feels like you're floating in a river being dragged back to your campsite, that's when it's good. If you read it and it feels like someone is constantly interrupting you when you talk (because you have to frequently interrupt for half a second to figure things out), then you need more work.
Read "Elements of Style". It's very very short but might help you a lot.