I solved this on my own.

I'm still relatively new to joomla, but I made out a way to add text bellow the main gallery display. I added a tag on the HTML of the template that loaded a module bellow the main body tag, and then I created a module that only shows on the main gallery page and inserted the text on the WYSIWYG editor that is available when you create a module in joomla admin

I hope this can be usefull to anyone

Cheers

I didn't use that option because I want to write text with different colors and some parts in bold and underlined, for example.

That option I explained on my previous post is good, but I found out it's not as good as I wanted, because now the text that I wanted to show up only on the main page is showing up on all RSGallery 2 generated pages

Is there a way to have my custom text (with the possibility of changing the font family, color, weight, etc...) just on the main gallery page?

I went ahead and placed the editor in on the config page for the intro_text although I did not use the editor for the comments I used the backend editor used for content, etc... hope this was ok.