Change "Who's online" text

Hello,
I have a developer license of HOT_sports template and I have some issues:

1) I can't find a way to change the text on the results of "who's online" module
2) I want to change the font of the whole template to Arial because it doesn't fit very well to the Greek language (half of the words in the titles appear as bold).
3) By mistake when I was on the control panel and I was editing the video player module, I clicked on the video image inside the text editor, changed nothing, clicked "save" and the video disappeared. How can I retrieve it?

I need your help
Thank you

1. That is core joomla module just find translation in .ini file in languages folder and replace it with something else. You some text searching utility to locate correct ini.

2. Replace font values in layout.css and template_css.css

3. This is default html: