Hello,
I posted the question to the studiopress community and got an answer. (just to keep this thread updated for anyone in a similar position as myself). They gave me this answer, and you’re right Davood, it would seem as though, with this fix, I would have to create a new theme file with custom code rather than just embed code in the functions.php
“You can customize which buttons display on TinyMCE editor in WordPress. Here’s a link to some code that can do it for you:
https://gist.github.com/JiveDig/83c2751199218724fd2a0233c338bb00
Keep in mind, WordPress is changing the editor to Gutenberg in Ver. 5, scheduled for release this Spring. Customizing the buttons will only work until then, unless they WodPress developers give us some way to keep TinyMCE around for a while.”
Given this response, I may just wait and see what the new update has in store rather than going through all this hassle if it is going to change in a few short months. Also, I took a look at the code for this fix and, unless I’m mistaken, it also looks like it would strip out other functionality like being able to underline and bold, which is not what I’m looking for – I only wish to disable the header 1, 2, and 3, options. Seems like more of a headache than I intend to get involved with so I will wait for this update and if the update doesn’t fix it, then I will try my luck with finding a solution again after that (haha).
Thanks again for all your help though, much appreciated!! ^.^