In a space battle, every ship would likely have all its crew suit up and drain the air from most of the ship to avoid sudden decompression due to breaches. Zero G would be normal operation, so everyone would be training in those conditions on a constant basis. Equalizing air pressure would also nullify the effects of flamers, gas, smoke, inferno, and sonic weapons.
Most small arms can only do cosmetic damage to ship interiors -Keyboards and consoles would be similarly protected with ballistic screens, as weapons powerful enough to cause hull breaches would also send shards of armor and structure fragments flying through compartments at hypersonic speeds. Bullets would be the least of anyone's worries.
Generic Marine Squad:
Armor: Marine combat suit, helmet with full A/V/Comms
1. Squad Leader- Blazer pistol x 2; Grenade loadout: Frag x 2, Flash x 2, Stun x 2; Vibro blade, Stunstick, Grapple rod
2. Marine- Blazer rifle; Grenades: Frag x 4, Stun x 2; Vibro blade, Grapple rod
3. Marine- Blazer rifle; Grenades: Frag x 4, Stun x 2; Vibro blade, Grapple rod
4. Marine- Blazer rifle; Grenades: Frag x 4, Stun x 2; Vibro blade, Grapple rod
5. Marine- Blazer rifle; Grenades: Frag x 4, Stun x 2; Vibro blade, Grapple rod
6. Grenadier- Grenade Launcher; GL Ammo: Frag x 5, Stun x 5, Anti-vehicle x 2; Vibro blade, Grapple rod
7. Sapper- Blazer pistol, Demolition kit, C8 x 10, Satchel charge x 2; Vibro Axe, Grapple rod
Each would also carry Medipac, Med kit, and the squad would have 1 Advanced med kit.
I employed the above loadouts in campaign for both Marines and Jump Infantry, with considerable success. The Jump Inf primarily used Auto rifles and the Grenadier alternated as the Machine Gunner, with the other Riflemen acting as mules to carry more ammo. The design is based off the WW2 German Rifle/MG squad, which was later adopted by most modern armies, with the squad dividing into two teams with the squad leader in the center directing fire.
The vibro axe was surprisingly effective in cutting through bulkheads, walls and floors, without alerting the defenders as a breaching charge would have.