Alright, so here are my results for Reflect Starmie: there was something that I didn't really like from the very beginning, the fact that with the listed spread Starmie wasn't even able to outspeed max Speed Heatran. In a metagame where Pokemon such as Heatran and Infernape are very common and threatening, it is notably important for Starmie to outspeed them or otherwise she could get KOed by consecutive LOed Grass Knot and HP Grass, respectively. Below I'll illustrate the damages that these aforementioned Pokémon score to 252 HP / 240 Def Bold Starmie:
Specially-based Infernape's Grass Knot vs. 252 HP / 240 Def Starmie: (48.77% - 57.41%)
Life Orb Heatran's HP Grass vs. 252 HP / 240 Def Starmie: (50.00% - 59.26%)
In both cases, the 2HKO is practically unavoidable. This, in my opinion, reduces Starmie's reasons of existence in a considerable way. What is Starmie going to do by using Reflect, Rapid Spin and that major investment in Defense? The answers are limited to: 1) stopping Tyranitar to an extent, at least one turn in which he sees it cannot kill Starmie due to Reflect + Recover | 2) take physical moves generally better, which in my opinion is kinda useless with that reduced movepool.
After having tried out sufficiently the listed spread in the strategy Pokédex, I started to use something different: 252 HP / 56 Def / 200 Spe. The spread is designed to outspeed max Speed Infernape while retaining some bulk in the Defense. Well, the outcomes of the tests with said spread were kind of unpleasant as well, as I realized later that the spread utilized by the Rapid Spinner set was slightly better than this one -- it basically makes Starmie able to take hits a bit easier.
In all seriousness, the only possible thing I could see coming out from a set of this type would be some sort of combination with Reflect and Light Screen and even Light Clay as the item. However, even without previous tests I really doubt it could work.
With that being said, I'm officially stamping this update.
Once the other QCers give their stamp, I'll move this thread.