swift/crit won't work until you have nightmare set, for now go crit/swift. For raids like argos, you'll use food to buff your mana regen. Use some combo of Reflux, hitmaster/grudge, adrenaline+keen blunt, cursed doll. Personally, I'd recommend Reflux, Hit master, Grudge, adrenaline as your 4x3, or Reflux, Hit master, keen blunt, adrenaline if you are scared of grudge for some reason. For daily/normal content like guardians, buy 12x MP efficiency books and swap that in, the full yellow engraving book costs like 300 gold or something. You can buy a 3/3 crit reflux/mp efficiency ring for like 50g and that'll prevent you from needing food for daily or repeatable content. You're technically a 3x3 for this, but not like guardians need 4x3.

Important though to focus on getting good CDR gems and the -cooldown tripods on all skills that have them available. You'll want to get +3s for now, then buyout relic +4s as soon as you hit 1415. That would be for Gravity, seraphic, rime arrow, esoteric, and (only once you get nightmare) rule enhancement on Frost's call. For legendary gear it's not that important, 2 pc argos and 2 pc valtan gear is fine, 5 pc argos until then. Once you hit 1445 obv go nightmare.

A lot of people say that instacast doesn't work at all before nightmare, but they're incorrect and parroting some dumbshit a streamer said. I've been playing it since 1370 and never once has the build not functioned or had DPS issues. I've been MVP pretty much every fight since Argos week 1 when I swapped to instacast.