Since the original discussion was about how new summoner has no depth, so I will use your points to highlight where new Summoner does fall into the concept of 'depth'.
1. Positionals. Whilst this is mostly seen as a melee concept, this does still apply to all jobs, in regards to casters, this is to do with where they stand and how that will impact them in regards to getting casts off. Now, whilst Summoner has very few casts, most of them are long casts (Ruby Ruin and Slipstream), so you have to be able to be in a position that getting those casts off is possible and you only have 1 Swiftcast per minute. Summoner also has to contend with a gap closer and melee strike straight after (Crimson Cyclone and Crimson Strike), so you have to ensure that you going into melee range for 2 GCDs is not going to impact anyone else in regards to mechanics. Whilst yes, the other casters also have to take these points into account, Summoner is also the only one who has to choose where these long casts are (as opposed to choosing when the insta casts are going), which is a different perspective to have to take. (You mention Lay Lines, but that is job specific and comes under positionals in regards to this point).
2. Uptime. This has obviously been a talking point in Endwalker as a whole, mainly in regards to Melee. All that can really be said for Summoner on this point is making sure the boss gets the full Slipstream uptime (though I do recognise your list isn't necessarily aimed at Summoner and so will contain elements that are applied in a more broad scope).
3. Slidecasting, Ruby Ruin and Slipstream can both be slidecasted. Again, same as point 2.
4. Raid Buffs is something most DPS jobs have to contend with, however, most are just fire and forget. I would honestly prefer to have something that brings more than just a damage buff, like Reaper's Arcane Circle or Monk's Brotherhood. Though Summoner does have a raid buff (and does feed with resources, ie Aetherflow).
As for the short list:
- Flare. this is a BLM only action D: that is unfar to the other jobs /jk. however, as I understand it, 'flare' is just the visual effects, which you cannot deny for Summoner, is impressive.
- Flavour, you can argue that new Summoner is too different from old Summoner, however, there were just as many people who didn't like the old Summoner aesthetic because you didn't summon big primals to do big damage, you know, like every other Summoner in the franchise.
- Intricacy is also a loose term because, what makes the job intricate? Is it the ability to move around your rotation to better prepare yourself for the future fight mechanics intricate? If so, Summoner does this, if not, Summoner fails. If it is more to do with how everything interacts with each other, then it doesn't fit that as well as it probably could.
- And lastly, does a complex job really mean depth? What is it about a complex job that means it automatically has depth? Infact, what makes a job complex in the first place? I almost suspect that, once you start trying to define complexity, you will have overlap with what people define as depth. So, is there anything that distinguishes the two?
It should go without saying that this discussion about what defines a job as 'deep' or 'has depth' is most likely going to be wholy subjective as noone is going to agree 100% with what criteria should be used to give a job their measure of 'depth', which is why you cannot take one person's word on their view on how a job is.