Support is one of my main components. I keep end eye on the map at all times to see if someone leaked behind the lines of ink, or act as a line breaker. That is what waiting for the gold dynamo roller is worth the chance...If it is, if I say so myself. I miss the ink strikes, and the bombs that it had with it. Curses.
If you ever want to be the one who defends the mid turf, or going over. You might want a tank like weapon, and a bomb sub that can keep the team from branching over. Blaster are good for recovering, and keeping such away from going too close, and it keeps them back. But make sure you check the length of it, some blasters are shorter than others, used for more offensive support.
Of course, the dynamos are GREAT for this. They are not meant for close combat, but to reach far to get the team quickly over to the other side. The sub for the current vanilla is great to keep track who tries to come up. Even if it doesn't get them, it will track where they are for a few seconds. The stingray could be a bit better, though.
I also love the tri-slosher. It's REALLY effective into getting places that are hard to see, and it's fast. It is one of a kind and makes brush users heads spin when used properly. This weapon is really good for support because you can get quickly behind the enemy and charge up your special. Also you can splat them in the face, then toss in a slosh to get a more quicker kill. (Learn to bomb cancel too...)
My other advises are: Be VERY alert, check your map often, prepare to sweat because you are going to be moving quite a lot to avoid contact and outsmart your foes, be smart and don't jump into the fray like your other team members, keep your distance and use your map knowledge to take advantage of the team! Do a lot of ink savors, or ink recovery ups, you will be needing it! Oh, also the ink savor subs.
You might not be able to do all the cool stuff like your warrior members are doing, but pretend that you are directing the machine itself, watching the missiles fly to the target. You can also direct your friends to safe places.