I just think:
1/ Year one gear should be infusable. VoG gear, Crota gear, HoW gear, old legendaries/blues/greens/whites etc all of it. Even if we have to re-obtain the updated versions of this gear(and it is at its original armor level, etc. The Legacy engrams system for exotics could be expanded to support engrams for legendaries, rares, uncommons, and commons. BUT these particular engrams would give infusable updated versions of our old favorites ... with the same stats they originally had of course.
2/ The addition of appearance slots which is in some respect: another tab in the character menu with a slot for slot mimic of the equipment tab where you can slot old/new/weaker gear that replaces the appearance of your equipment. WITHOUT effecting your stats/performance. This excludes things like weapons, ships, and emblems of course. (Shaders in appearance tab could affect only the gear slotted there... allowing for a two shader 'piece specific' look).
Appearance slots in unison with Year One gear brought forward would remove ANY and ALL problems regarding year one favorites feeling 'left behind'. Hunters who kept(or deleted and want to re-obtain) their white starter cloak could stick it in an appearance slot while keeping Raid useful gear in the cloak equipment slot.
3/ ALL exotics to be brought forward to year 2+. Necrochasm was possibly the hardest weapon to obtain in Destiny ... to date at least in terms of time spent and logged objectives. Why it is left behind is beyond me, the creator of that weapon must of felt like their kid got expelled.
This isn't really a huge thing but, maybe a catalogue for all the legendaries we've collected. Much like the exotic, shader, ship, sparrow, etc catalogues. A collections kiosk for legendaries... where you can re-obtain old favorites even after you have scrapped them(for vault space/materials etc). It would work in the same way in that the perks are rolled each time, and it costs glimmer/resources to obtain. This would work well with the first two points. For reasons I do not have to explain in this already long rant.