Altering of interface for real estate agents login

We have a lbs app that uses the porpoise interface ([login to view URL]) to add/edit entries in the database. 1) We need this interface enhanced so that we can give estate agents their own login (this is already possible) but they will only see their listings (this is not currently possible) 2) we need the interface to break up the listings into pages with 50 max on a page (currently it lists all on one page 3) we need the add listing process to go directly into taking the required information as opposed to what happens now 4) we need an extra feature that allows them to upload an image which is then hosted at an image hosting service and the url inserted into the database for that listing id