If he has both a bolt pistol/boltgun and a close combat weapon and the option says that he may replace "and/or" then you may give him lightning claws as he is simply replacing each hand with a lightning claw.
If you look closely it's why the single claw went to 15 points when it used to be 25. so that the total between the two is 30 and they don't have to put extra entries. though it does take reading it carefully to pick it up.
I looked at it for a bit as i have a captain w/lightning claws and a jump pack and wanted to make sure i didn't have to run him as a
SC since i didn't want to spend that many points on him.
The command squad doesn't need to be attached. It's now an independent unit. Also the days of just buying a character to add to the squad w/out taking up a
HQ slot are gone. You can no longer buy that third
HQ choice inside of a command squad like in 4th edition.
Hope that helps.