You realize there are plenty of tunnels that go under the ocean/bay right?

A subway is just an underground railroad. there are no requirements on the technology to how many stops per mile you have. Subways can also go straighter then above ground routes.

Yeah the humans will be in the carrier not in the "fighters". You cant bank off anything in space fighter planes make no sense. Most fights will happen millions of miles away from eachother anyways with sensor based fights and not dogfights.
You already see this in modern fighter jet fights. If you have visual on an enemy fighter jet its already too late. They fire missiles from so far away.

Yeah it makes everyone feel better and more relaxed if the first date has an easy exit and low commitment.