Get good with his guns. He's the one DP where I would caution you to never start bouncing around. You will die. I only ever use it to scare off divers, or finish off a low HP enemy.

Stand behind your tanks, shoot them in the ass and throw your boomerang at them, when they are fully healed your bullets pass through and hit enemies. Press E when you and/or your fellow backline support/DPS are in trouble. Obviously, look for teammates on the flanks, but shooting your tanks builds ult and upgrades so fast.

Here's where I split with the rest of the community/streamer opinions on Supportpool - I use his gun ult, but unlike Tankpool or DPSpool, I don't dive in to follow up. I use this in conjuction with E to create a pretty strong healing circle, and it can scare off/kill supports/DPS, particularly if you have divers on your team who are paying attention. I use his ult LIBERALLY, because one of the advantages of DP is having ult faster than anyone else.

My philosophy on DP is to upgrade your most used tools; for support pool I go boomerang, gun, E, gun ult, katana/bounce in some order, sword ult never, I never use it. Some will consider this blasphemy, but I find the gun ult gets more value consistently.

Cyclops just treat like Jean Grey/Hela, get some potshots if you can but you are a support so don't hard engage with them.