1. Google Webmaster tools works but is better safe than sorry.
2. Using CSS to render the top tabs (at the moment you are using onload for tab images - javascript), you can achieve the same effect and have normal text as anchor linked to the pages you have on your website.
SE can not read the content in images.
3. Yes but make proper use of them - 1 x h1 tag is enough - don't abuse it.
4. Thanks
5. Google - the internet is full of how to... - most is down to experience and patients ( a lot of it)
6. Directories are not a bad idea (doesn't add to much value either - gets your link exposed) but too many at one time could be bad, so take it slowly...