To answer your second question first, as it is the easier of the 2, I found in this article named Mac Basics: Modify your windows found here: http://support.apple.com/kb/HT2487.
Customize the toolbar
You can customize the commands available in your toolbar.
- To change the contents in the Finder window toolbar, choose Customize Toolbar from the View menu.
- In the dialog sheet that appears, drag whatever items you want to add onto the toolbar (such as Burn, Eject, Get Info, and more).
- To remove a toolbar item, simply drag it off the toolbar.
- To rearrange stuff in the toolbar, just drag an item to the desired location.
- To group items so that they appear separated from others, drag a "Space" or "Flexible Space" item to the toolbar to create a separation.
And for the mouse settings resetting issue, here are 2 articles that should help you isolate what may be causing the mouse setting to reset. First this article Mac OS X: How to troubleshoot a software issue
And here is some information about troubleshooting you the mouse settings resetting on you. First this article named Mac OS X: How to troubleshoot a software issue found here: http://support.apple.com/kb/HT1199. It outlines how to see if the issue happens across the system, or in just 1 specific user.
And this article named Isolating issues in Mac OS X found here: http://support.apple.com/kb/TS1388 will help to further isolate an issue if needed.
All the very best,