Hi
ywp033402I agree that a higher GMAT score could make your profile more attractive to top schools ... although you haven't told us much about the rest of your profile, in terms of industry, previous roles, unique experiences, etc, which could help differentiate you from other applicants. To address your questions ...
a) If you cancelled the scores from your January attempts, those attempts do not show up at all on your GMAT record, so adcoms would only know about these attempts if you mentioned them.
b) Is there any point in retaking the exam if your ability level does not increase? Well, we typically say that scores on test day can vary +/- 20 points, so it's entirely possible that you could score 10 or 20 points higher on a new exam, with no change in your underlying ability level.
However, it sounds like the big limiter here is your verbal, and if you could get some movement there, you could go into a new exam with an
expectation for a higher score (instead of relying on luck). Do you truly believe you are at the absolute ceiling of your verbal ability level? Have you already spoken with any expert coaches/tutors about the types of mistakes you're making and how you might address your weaknesses?
Best, Jennifer