Hi Leonardo,
I know little about dreamweaver - I don't want to. I still do all my web stuff in raw html, but that's not often, these days.
I think, if you view the source code for the thumbnail pages, it may show the code for linking the thumbnail to the large image. If you copy that (alter the file names accordingly) and paste it into the home page for each image, I reckon you can get it to link to the gallery from the image. I would guess there is a function for doing that.
I understand your idea of the vcr controls, but it does not map correctly. If a gallery is a tape, then fwd would show each image - as a slide show, you'd have a button for the first and last (in your proposed example the first takes you to the gallery - eject button should do that ;-) stop would stop the slide show (and give a blank screen.....) pause would stop the show with the image showing until you hit it again (or after five minutes a blank screen), and add fast fwd and single frame .... You could spend most of your life doing that.
Another thing that may be useful. If you are developing your site, then for your home page -www.xxxx/index.htm or whatever - put a holding page - like your contact details and explain the full site is coming soon - then when you want public comment, load up your web site, but with its home page as /index2.htm, say. Then point your testers to index2. That way, the casual viewer will not see a sequence of changing broken pages, etc. As you finalize concepts, you can copy them over to the main index.htm page and its links. But, then it may be good to let everyone see the struggle in development of the site.
Best wishes,
Ray