Re : galleries question
You must change the smarty templates templates/tiki-browse_gallery.tpl
Personnal advice:
If you use only your theme, create a templates/styles/you_theme/tiki-browse_gallery.tpl
If you use only on theme of the tiki theme, create your own theme by duplicating the one you have, and do as above
If you use a lot of theme, change in templates/tiki-browse_gallery.tpl
For the instructions, look at the url of the page and change the templates/url.tpl where you change .php with .tpl