Perhaps you’re rebuilding the BP-theme to your liking and find that you want to link to specific pages for the user. This is how you do to get the users to those pages:
<a href="<?php global $bp; echo bp_core_get_userurl($bp->loggedin_user->id); ?>profile/change-avatar">Change avatar</a>
You can change profile/change-avatar to the pages in the bp-theme.
With this you can for example put everything from “settings” on the user profile page. That way you’ve got one page less and one thing less on your userbar.
You can make things dissapear from the userbar/optionsbar with using the css-command display:none. Google for it.