For the first question – easiest to look at the FAQ for more detail: http://codex.simple-press.com/codex/faq/problem-with-post-edit-buttonow-to/problem-with-post-edit-buttonow-to-delete-a-topic-or-post-and-other-tools/
On the second then this is constrained by your Wp theme so you need to allow for more space on the template you are using for the forum page. For example – if you arr displaying a sidebar perhaps you could remove that.
I did remove the sidebar and its still to small any documentation on making it bigger?
This is still a product of your WP theme where it will have defined the container to a fixed width. We cant really produce worthwhile documentation because every Wp theme is different.
If you give me a link to your site then I can take a look as you can find out with tools like firebug very easily.