How to batch download and process camera roll
Apple has Photo Stream for this purpose. As long as you launch iPhoto once every 30 days (at least) it will get all your photos from iCloud. You can then delete them off your phone once you know they've been imported into iPhoto.

Alternatively, you can set up Google+ Auto Backup on your phone. As the name implies, it will auto-upload everything you take to G+. If you let it resize the images to 2048px it won't cost you anything either. Auto backups default to private so nobody but you can see them.

Both of these options will automatically create albums based on the date.

For quickly deleting everything on your phone, launch Image Capture on the Mac. (It's in Applications, comes with OS X). You can set it to automatically open iPhoto, import and delete when the phone is plugged in.