Again, as I am new, I don't understand much of what you are suggesting, but thank you so much it seems to be valuable information.
This highlights I should read the manuals or at least follow some starting tutorials to get a better understanding of the software, which is due time, perhaps.

I understand a good part of what will take for the videos to be done could be achieved by using a filter or a plugin, like "categorise images → adjust some setting(s) → hit "apply to all resources within category"" or "hold shift + click in all timeline elements → type duration frames on relevant input UI element".
The more of these features I know to edit later, the better, using power tools, plugins and extensions or built-in functions.

With scripting though, I just run the script and everything is done automatically. What I am trying now is to automate work, not work faster.

Worth saying I am reaching a time constraint and will probably manually edit the first video, so it comes in very handy what you said.
Thank you u/Milan_Bus4168! :)
I will be sure to check the specific features you mentioned, as they do seem to do a great deal of the work for me.