Scouts are decent backfield objective holders. For blood angels, Vanguard Veterans are amazing. You may want to take the jump packs off of the assault squad and give them a rhino. And the librarian's force sword comes for free
IIRC.
I'd take the power fist off of the assault squad... give him a power sword instead. Likewise, the
tac sergeant should probably just have a power sword. Both marine squads should take the meltagun and the tacs should take a missile launcher. You should have a variety of options for cracking armor at that point.