I don't think the dev team has any strong opinions on job balance, unfortunately. Most of the views that they express are simply a function of what's being shrieked the loudest on this subforum. Even the parts about casters deserving to be top dps because of the larger hitboxes that happened to be present this tier essentially was pulled right off this subforum. The concept of 'difficulty' equating to more 'damage output' is similarly a completely new one, and one that was pulled off of complaints early this expansion. SAM are simply in a privileged position because the players spent the past 8 months shouting everyone else down in here over Kaiten. They really don't have a vision or consistent design philosophy. They're just trying to mollify everyone, which leads to everyone being unsatisfied.

My own preference is that jobs get a level rdps playing field across the board, such that player skill reigns over job selection. Otherwise you end up with overpowered jobs, like 4.2 era WAR and current SAM, filled with swathes of absolutely mediocre players who are completely carried by their job selection. And those jobs end up staying in positions of power because everyone knows that if things were equalized, those players wouldn't cut it on anything else.

The regen/support argument is also likewise an excuse. There is no reason why certain jobs like SAM and BLM should universally be in a privileged position. If these minor support flourishes are such a big deal, give the 'selfish jobs' flower growing powers that have no dps relevance and nerf their damage output accordingly in line with everyone else.

RPR's gauge generation is actually pretty close to mathematically perfect, once you're comfortable on a given fight. The real problem is the damage weighting, as you said. Raising the average GCD value on a burst focused job doesn't work out so well, because you're weighting the part of the rotation that has the least value. If there was a way to get a second Enshroud on pull, that would be nice, but it seems like a deliberate decision to place more emphasis on the 2 minute burst and onwards.