what is there is good. but there should be more mention of arrangements/song writing which is crucial. i'd also include recommendations for bands to do demo's of the songs they intend to record before any proper sessions take place, even if they are really rough. ideally its good to be at a few practice sessions with the band and get them inspired and thinking about arrangements. can also get them practicing the songs until everything is as tight as it needs to be prior to recording.
for metal id recommend a sansamp for bass pretty much every time (or at least to have the option of it). classic guitars like les pauls, telecasters, strats etc always seem to have their uses, as do "vintage" amps, even if they arent for the main parts.
id also include things on drum hardware, stable stands and adequate felts for cymbals are really important and make a difference. wobbly stands=phasey. cymbals clanking horizontally against metal stands=piercing noise.