Final Question: Is my conclusion that the stat-power of gear grows exponentially as you move up through the levels correct(ish) or does that conclusion provide some clue that I'm already woefully off target with my current toon; and if the latter what might I be missing (apart from the obvious answer - experience)?
just giving an example, and i hope that you understand this.
at lvl60, you see only people which has more then 1200 stats which can do fine in VR green mobs. even better if they have 1500+ stats.
look to the maximal stat points that you get at lvl 60, that's with UM, so 10 stat points ( i've counted the free LUC in it ) multiplied with 59 ( lvled 59 times ) and you comes out on 590 stat points.
a NPC gear ( or in this context, why lapis is more important, going to use dread/legend gear which isn't lapissed. ) the stat per piece is ~30. going to include the slotted dragon helmet, which is 6 times 30 = 180. With accessories, you ends up with < 225 stats (legend accessories, +15 * 3 on useful stats, so counted only the +15 on LUC/STR/DEX) if it's not linked.
counting those up : 590 + 180 + <225 = <995 stats.
that's 2/3 of a 1500 stat build. So 1/3 of it is linked with lapis.
for a HM it's <877, about 0.6 of a 1500 stat build.
at lvl70, you need 2000 stats if you want to be competitive in several dungeons and PvP.
the gap between stats from your toon and lapis will become bigger, so about 0.5
this is for PvE ofc. in PvP, people have a higher stat builds; like in EP4, when the cap was still at lvl60, there we're people around with 2k stat points. in that period, legend accessories didn't existed, people has dread ones, so less then 225 from accessories only.
without lapis, you've less then 1000 stat points while in PvP you've more then 1/2 of your total stats from lapis only.
that's why lapis is becoming more important in PvE if your lvl goes higher, but more important when you want to PvP