Hello again Desi!
I feel like you and I have a lot of similar strengths and weaknesses on this test based on our previous exchanges, so maybe I can help out a little too.
First, I'll say that such inference questions are usually weak points for me as well. RC in general tends to be my weakest section right now because I think it may be the hardest to complete on time (accurately). That said, I've read/seen/done a few things that have made such questions a little easier.
One of the big points goes back to what atierney just said: An inference question will
have direct support! The unfortunate aspect of that is that you won't find direct quotes that line up with any of your answer choices, so it may require a little more "digging through the passage" than usual. I may be wrong, but your issues here sound similar to the issues you said you have with long LR questions. Inference questions on RC go fastest when you can retain a good amount of information from the passage and therefore spend less time digging to find the support you need for the correct answer. Fortunately, I find that most inference questions like that come at the end of a passage when you have likely already looked back through the passage a few times for previous questions, and so your eye for the passage should be a little more refined than it was during the first questions. What I usually do first, before I even look back through the passage, is to eliminate answers that are clearly wrong. If you have a good understanding of the passage, you should be able to eliminate at least 2-3 without issue. As far as options that are clearly wrong go, I'll refer back to my previous post about LR by saying that any answers that make you think "Huh?" should be quickly axed. From there, I approach the remaining options similarly to how I would a LG question: I'll check the options against the text to see what fits. Again, if you have acquired a refined eye for the passage, it should not require re-reading the entire passage to do this.
As far as your issue with misreading/misunderstanding one particular word that throws you off, I TOTALLY get that! It was one of my biggest struggles when I first started doing timed work on both LR and RC. The solution to correcting that problem is simple but not necessarily easy: You need to remind yourself to pay close attention. I'm guessing that you are very good at doing that in untimed conditions, but once the pressure is on, your eyes get ahead of your brain and you miss things (same thing happened to me). What really helps with this is (again going back to my post on LR) is taking your time to get comfortable with the pacing. Once you know how fast you need to go and get comfortable at that pace, you won't stress as much when reading and can slow down your internal clock.
I'll also refer back to what I recommended before about using a pencil/pen to track your reading as you do the passage or a longer question like that (you could theoretically use the cursor on the computer for this in the digital format). I adopted that method purely for the purposes of reading the passages faster in RC, and as I go I will underline key points in the passage to make referring back to it later a faster process. If you can get through the passage faster (without sacrificing understanding), you have so much more time to tackle the questions, especially tough/long ones like inference questions.
Again, RC is a weak point for me, so I may not have the best advice ever on this subject, but these things have helped me out. Good luck