Some of my ideas and questions

[Suicide Junkie]

The requirements merely indicate howmany are required for a legal design.

In actual use, ships with 1 or more functional lifesupports run at full capacity, and ships with zero functional lifesupports move at 1/4 speed.

Since you're modifying the hulls anyways, you could set the lifesupport requirement to zero or one, and it would be satisfied by the built-in hull ability.

My reason for leaving the requirements as-is, is that I consider the racial trait description as "Vaccuum Exposure Resistance", not "Lives in outer space".
Ie: crew members can survive being in a vaccuum for extended periods, but not indefinitely.
Thus, they can finish the battle using supplies stored inside their bodies, or in always-on environmental suits.
Additionally, the crew would have to have the ability to hibernate until the ship is repaired or another combat situation arises.
They can still fly home at full speed, since most of the crew is not required to run the engines.

In fact, I will increase the lifesupport requirements of all the hulls by one, so Escorts require two. The escort's requirement will be satisfied by the addition of one LS to the hull's LS, resulting in a normal escort which is not hampered by the loss of its LS component.

In order to make the racial trait more useful, I might do the same with crew quarters. Total trait cost, maybe 250 points.