Some answers below...

1. I would like to search a word on a module  - I can't find the search icon and by using Ctrl+F it pop up the find of the  browser find - this option is searching only on part of the module. Is there a search option which will search on all the module artifacts?
[dmoul] You can use the quick search in the upper right and limit it in some ways. But I don't see a way to limit it to the current module. I hope someone else will chime in with a more specific answer.

2. Using the speller is not working in the browser (Chrome and Explorer) as expected - I don't have the list of suggestion. and ideas? (I can see the suggested using other application on the same browser)
[dmoul] Hmm. It used to be that Control-right click would bring up the spell checking and some other native browser context menu options. I just tried it on jazz.net, which is currently running a 601 release candidate. I'll ask around.

3. attachment of a file in DNG (like in word) that when user click on it, he can open the attached document Is it possible?  
[dmoul] You can upload an attachment as separate artifact. If you see it in the Artifacts view you will get a rich hover. You can highlight and copy the title, which is a hyperlink. And you can paste that into another RDNG document in-line with other text.  For certain special file types (e.g., PDF) you can add the artifact to a module, and it will show a preview. I believe you can click on it to open in a separate tab.