Yeah. I think it was written during 4e; there's some stuff in there I don't get. (Last Man Standing, familiars for librarians, and a couple other things spring to mind.) Two points for +1 Ld for the squad is... yeah. (Cigars.) The Tome of Infinite Rage is 50 points, gives massive buffs to every Angry Marine on the table (not just in the radius of the Chapter Master/Chief Librarian), and debuffs enemies to the tune of -1A, -2Ld. Their captains, for 75 points, give +1 Ld to Angry Marines and -1 Ld to their enemies across the whole table; twice this if within 24".
Balancing this, they have no dedicated transports aside from Land Raiders (Rhinos are not angry enough) and their Tactical Marines cost more than normal and are only BS3.
Basically, the thing's a joke codex, as I'm sure you're already aware. It's poorly balanced at best, and if you ever get a TO who will let you use it, I'll be shocked.