If you're near a planet, you can't dismiss the ship like you can with an SRV, so it is at risk unless it has an AI pilot.
If your ship has no pilot, it will continue doing the last thing. You're best ensuring it has stopped motion before switching to the fighter. Ensure it is parked somewhere safe, too.
I don't know if it's possible to launch a fighter whilst on the planet surface. I suspect not due to ground clearance.
Nah not possible unfortunately. When you drop below a certain altitude (not sure what) the Deploy Fighter option goes red and is inaccessible. Also, you can't lower your landing gear when a fighter is Deployed. I would have liked being able to Deploy fighter Ai then land then deploy my SRV. The fighter could protect my ship and me cover while I'm in the SRV. Maybe even attack wanted Skimmers Etc if I gave the command. That would have been fun. Even if your ship "dismissed" because you went to far from it in your SRV, your Deployed AI fighter could follow you around the planet. Lots of potential for fun. Hope fully some day :/
It is fun! The fighters are excellent at canyon runs. And if you need to land, you just dock on your main ship and land and deploy your SRV. Your ship is just nearby - you may have to wait a bit on it since it probably can't keep up with your fighter.