Discovered the following resources, but had no luck implementing the solutions they provided to achieve the above:
https://community.atlassian.com/t5/Jira-questions/JIRA-Edit-Screen-Remove-quot-Comment-quot-input/qaq-p/21871
https://jira.atlassian.com/browse/JRASERVER-12244
I tried all scripts provided, and in all cases, the custom "Hidden" field does get hidden on the Edit screen, but doesn't hide the Comment field (on any screen), which is what I'm trying to achieve. I checked to make sure that there's a separate Screen associated with each Issue Operation (Create/Edit/View) in the Screen Scheme, as I thought that that might be the issue. I made sure to place the script in the Description, and I believe that that part was done correctly as, otherwise, the Hidden field wouldn't be hidden (when I remove the script from the Hidden field's Description, it shows up in the Edit screen, and only the Edit screen). Reindexed (as JIRA kept yelling at my to do so), but that didn't change anything (as expected). Currently running 7.3.3.
Someone mentioned that this can be done using Behaviours as well, so if anyone can provide some direction on how, that would be great as well (in case we can't get the script method to work). There was also a mention of using a CSS Banner method (which I successfully used to hide the Assign button on the View screen using info from another thread), but the example given is for a Transition, and I assume that I would need Screen ID instead of a Transition ID to get that to work.
Looking forward to hearing your suggestions 