It seems like if you have a pocket passer you need an elite O-line. If you have a mobile QB - O-line just has to be good. But what you MUST have - no matter what type of QB - are weapons on the outside that are playmaker / game changers.
Right now we have a so-so line and an immobile QB with no real game breakers at WR or TE. Really the biggest playmaker at this point is Cupp - who's one of the best slot guys in the league. That's a start. Other than that we have solid chain movers in Woods and Reynolds (now Jefferson) and Higbee.
Not sure what we can or cannot do this offseason but changes need to be made. If we stick with Goff we need to upgrade the line AND add playmakers. If we somehow go a different direction with a more mobile QB, we can tweak the line (Center only maybe) but we really have to add some speed and/or size outside