Opportunities page customizations and modification suggestions

Certain portions of the Opportunities page (http://civivolunteer.ginkgostreet.com/civicrm/vol/#/volunteer/opportunities) should be easily customizable.

-The title is currently CiviVolunteer. An organization should be able to change that to something meaningful to users like "Volunteer Opportunities".

-The Role field should be easily hidden. Some organizations will have a huge list here and more than a user wants to sift through especially if location is more important to them than role.

-The With field should have the ability to be limited in search scope to a group, a contact type or hidden altogether. Currently, it is not usable at all for an unauthenticated user because they don't have access to the appropriate contacts.

-Within should start prefilled with some number (customizable or otherwise). The ability to remove km should be provided.

-Street address and city should both be hideable. Country should also be hideable and set to a default if appropriate.

-The results table should be sortable by clicking on column headings. As of right now, they appear as links (the cursor changes on hover) but clicking them has no result.