Your best guide is:
DrDrizzay
For the bridge part, you can basically camp the ogre spawns once everyone is across. Avoid using rocket launchers and grenades that can kill you from friendly fire. Shotguns kill the ogres really quick. Use defender titans with bubbles to keep your health up, helm of saint blinding bubble is very useful.
Same for Deathsinger, avoid rockets at all costs and use blinding bubbles on the knights. If a hunter has Celestial Nighthawk, you can one-shot the Deathsinger with the super.
Yeah, if you have done 28 then you can join someone else and have them load you into 32.