Which email-setting do you want to change?
If you mean the mail-adress, that you entered in the setup process, you can change this in the .ini files. Look for /settings/siteaccess/shop/site.ini.append.php (or similar). This countains some basic data from the setup wizard.
The the other problem: Looks like a template problem. Did you check the bug reports, if this was already reported?
