Hey Jesse,
You can edit both of these things without modifying core files. For the page title, you’ll need to tap into your theme wherever the_title is being called (page.php or header.php likely) and conditionally set the title for the community pages with this conditional code:
if(tribe_is_community_my_events_page()) {
echo 'were on the my events page';
} elseif(tribe_is_community_edit_event_page()) {
echo 'were on the add/edit events page';
}
For the “Not %user%…”, make a copy of /wp-content/plugins/events-community/views/my-events.php and place in an ‘events/community/’ folder within your theme and edit away!
I hope that helps,
Jonah