Don't panic, in your mobula you can use your excellent balloon and quick speed to avoid fire. The only thing you need worry about are squids and blender fish. Never be afraid to burn kero, it's a very important tool.
One reaction is to move down and burn kero to avoid fire. I'd recommend having a flame up on the right wing for the gunner to go to. This position can aim up very well and harass, it's where I put my mine. Just make sure not to forget about the top engine. Once you get a good position you can hydro up to use your other guns. On a high map like fjords you can survive a very long time by staying underneath. Watch out for weapons like hades though.
Going up is another tactic to avoid fire, however pilots usually bring hydro so it generally buys you less time. But being above is usually an advantage. Whether I go up or down is situational, but remember that most guns shoot better down. And your armor is on the top so moving down exposes you. A large amount of shots will hit the balloon if you're high.
My reaction is usually to dodge and burn towards a charging ship to quickly avoid arcs. Start your turn early and get ready for all guns. Using your balloon is generally only a means of tanking so you need to rely on superior positioning and your [flame] to get out of a tanking position. Know what they are doing and turn and burn accordingly.
I have my keys remapped so map is C. I tap it to see where a ship under or above is pointing/turning. The throttle keys are very annoying because it's often crucial to quickly change direction. I'd recommend a mouse with side buttons you can quickly tap with your thumb. You can find cheap gaming mouses online.
If you need to quickly go down but your balloon is damaged just burn it out and drop like a rock. Use drogue chute when necessary. Make sure to immediately turn it off when your balloon is rebuilt because it reduces thrust.
If your balloon will get popped very soon burn hydro. Sometimes it's good to burn it all the way out and start using drogue, other times leave some balloon. Be careful not to lose arcs because carronades can still aim up well. It's often useful to use hydro as soon as your balloon is rebuilt.
Moving up and down can be used to dodge long range gunners. Moving up will often cause them to hit your balloon. This will mess up your gunners too so be sure to tell them what you're doing. In general try to stay still for your gunners.
The merc mob can out range basically anything so make sure to use that advantage. I dislike double artemis because it kills slow and is kinda cheesy. The Ducks call them cheese mobs. I much prefer a lesmok (or heavy) light flak and gat on the left side. I used to do a left side banshee carro with heavy clip. Heavy makes the banshee accurate at longer ranges and is excellent on carro.
In sniping matches find cover that you can use to duck behind to repair. Against brawler ships pick a place with lots of open space. Move backwards when they come for you. Burning kero can buy you more time, then move up or down and fix engines. This may make your turn slower so judge the situation.
If you're fighting a merc mob try to take out their merc first. Whoever does the first disable is usually the winner. A common loadout is an engi on top so they can repair faster than a gunner, or carry a buff hammer (or spanner mallet buff).
If you're fighting a double merc you must expose yourself to theirs. As long as no one else is shooting you can just keep shooting because double merc takes much longer to kill than your loadout (and an artemis is a much better disable weapon). If you need repairs you can dodge them. Another option is using your merc and other gun while the engi tanks the hull.
Against Pyramidions I'd highly recommend having your merc only aim for armor (unless you can shoot their engines). Trying to aim for guns can cause you to hit the balloon. Pyramidions have mediocre armor and hull so you need to do as much armor damage as quick as possible. Try to aim for the lower part of the ship.
Always give out loadouts. Your engineers should probably bring fire extinguishers. For the merc gunner ammo you might want lesmok charged heatsink. The lesmok and heatsink are for the flamethrower. Make sure your gunner doesn't use lesmok on merc because 1 shot every 6 seconds is nothing. Also I'd really recommend bringing a fire extinguisher. You can jump and put the top gun out and if it's safe you can go extinguish the main engine.
Always start turning early and check their position. Try to have as much open space to engage with as possible. This doesn't necessarily mean camping, but move around and experiment with different positions on the map. Having vertical cover is very useful.