Taking the tutor's advice into account, I've refined a bit what I feel like Ling Qi should have as a 'path', and it has three components. She could just focus on one, of course, either exclusively or as a base (more or less abandoning the rest), or she could add in more items, but I feel like these can fit together - at least for this stage of her cultivation (I suspect a cultivator's journey through Green involves a lot of pruning and revising of arts - which would be why the Elders aren't really all that concerned about their disciples learning arts that don't fit together conceptually*). These components are (1) Argent, (2) Moon, (3) Music. There's also (4) Archery and (5) Wind to consider, but I feel like those aren't the same. There's also the question of (6) Thousand Ring Fortress and Zhengui.
1. 'Argent' is a shorthand for the balanced path that Master Yuan took, which the tutor warned was difficult to follow, especially "scattered". However, its balanced nature makes it an excellent "learning set" and means it's unlikely to be incompatible with any other components. The coverage of eight elements suggests quite a bit of flexibility - and so far the arts themselves seem to be pretty useful (AC and AS are still in early stages, so still seeing where those go). It also likely helps to mitigate any extreme personality impact from elements and, given as this is Yuan's sect, there is no danger of lacking materials to further this component. I would want Ling Qi to pick up the foundational arts, master them and then the two Cultivation Arts. Now, whether she should go any further down this path...? Probably not. The four Combat Arts and two Cultivation Arts are sufficient here. It might even be that Ling Qi puts aside the four Combat Arts some time in Green - their role being more of a learning tool and balancer as Ling Qi figures out her path. Or perhaps she'll move further towards these "contradictory element" arts.
2. The Moon is going to offer quite a bit of Yin and Darkness. Note, however, that two of the three arts have other elements (I wouldn't be too suprised if Sable Crescent Steps picks up something else - Wind, say), and those are compatible with the other two components. I'm not sure if every Moon-type art is going to have Darkness, mind you - the ones so far are from the Grinning Moon, after all. There's a lot of emphasis on secrets and hidden things in the moon thematics, and I recall one of the phases is associated with music. Ling Qi has really immersed herself in the (Grinning) Moon thematics, but how much of that is really her lingering pre-cultivator life and the deliberate coaxing of a spiritual patron and how much what she wants to be in the future? I do see her as not being limited to a 'thief cultivator' even if she keeps the Moon theme however.
3. Ling Qi only has one Music art (so far), but this definitely seems something that's important to her - heck, it's just about the one hobby she's expressed over the past year that isn't "get stronger" or "nick stuff and stay alive". It also can come almost directly under Moon and, so far at least, the Argent Arts are well compatible with musical attacks. Given Ling Qi can play music without anything so mundane as the need for air or even sound to carry it, it's in some ways the most supernatural of her capabilities (well, it's all supernatural, but hey, music, spheres, etc). While the Argent component might end up simply being "training wheels", as it were, I don't see Music leaving ever.
Now, these are the three components I feel Ling Qi should pursue, at least in the near future. What does this mean? Well, for one, I feel that she shouldn't pick up any more Arts that don't fit together with at least one of the above - more is desirable, of course, and I wouldn't want her to pick up more Argent-type arts beyond the foundations without them being at least connected to a 'second tier' component (see below). And definitely no Cultivation Arts unless they're musical in concept. Yes, that means that I'd be pretty hesitant on her picking up a Wind cultivation art (say, from Cloud Tribe loot).
There are, however, two 'secondary' components that, while currently more a matter of mechanical utility than desired thematics, might end up being promoted.
4. Archery is, as even the proponents seem to admit, a utility skill and not, as for the tutor, a path towards the peak. Archery's been pointed out as a way to force enemies to get close into Ling Qi's misty "domain", or a way to harass from a distance before disengaging, or even early on, as a way to deliver damage. There's not a lot about what an archer is, what it brings to Ling Qi's character or anything like that - just "this is a way to damage or constrain the tactics of enemies". Once FSA is mastered, I would probably not recommend Ling Qi pick up further archery arts unless they fall under Moon or are an Argent archery art (or fits with Music, although that might be a bit rarer). Mind you, it's a useful tool, and one that shouldn't be incompatible with any of the three 'primary' components, but it's simply not broad enough to make for a basis for a path.
5. Ling Qi is quite talented at Wind (there's a bit of a question mark there - I do wonder what would've showed up if she hadn't picked the Wind art and mastered it). In fact, she's got several arts that take advantage of that. And it certainly has the breadth for the basis of a path (at least in part). However, it doesn't really feel like a 'primary' component - probably because while an element is broad, it's sort of subsumed into the Argent component in some sense. Maybe if Ling Qi picks up some arts that are both Wind and one of the other components it'd feel more integrated into Ling Qi's nature - but I donno; Wind, while an element, doesn't seem to feel as 'characterized' as Darkness or Music.
6. Thousand Ring Fortress is kind of the odd man out, as it were - Yang instead of balanced or Yin (admittedly, FSA is also Yang; to be honest, I'm wishing Ling Qi picked up a Yin archery art), Wood instead of part of the Imperial Eight or Darkness and otherwise not really meshing with the rest other than in utility. I'm kind of in favor of Ling Qi retiring it, to be honest... with one sticking point. Zhengui, who's Wood and Fire, growth and destruction. I'd kind of wish that Ling Qi could sort of 'foist' TRF off on to the little guy (I donno - it might be possible, I suppose) since it's just not really meshing currently. It's a strong art and useful... but it's still an oddity. This might change in Green, of course, as the path evolves.
7. Zhengui is Zhengui. It's really tempting to pick up arts that synergize with his elemental nature - both for the learning bonuses (which, admittedly, are currently not all that significant) and for the thematics. But I don't think that Zhengui needs to thematically match Ling Qi in some sense for them to stay together. And, heck, even so while he's a cycle of growth, Ling Qi could be a cycle of elements (Argent) or a cycle of phases (Moon).
We'll see what Green looks like, of course, and the inner sect. And to some extent, accepting or rejecting Renxiang's offer will have an impact, along with Ling Qi's other decisions. As for where to go in her cultivation... well, again, I suspect that Green will change our perspective as mechanics are revealed or shift. I'm wondering if permanent bonuses from breakthrough aren't strictly speaking truly 'permanent' (that is, if Ling Qi completely ignored Wind during Yellow, she might see that +1 initiative vanish), for example, or if meridians change in their nature, becoming easier or harder to re-adapt or are replaced by something similar (as bodies become less like a mortal's and more like a spirit's).
Up until Green we've got a good idea of what she needs to get - more levels of arts she already has, the fourth Argent foundational art, maybe a few more meridians and a bit more qi if she can.
* They don't give advice about keeping a focus and, moreover, Ling Qi was given (as "art that'd be useful for her") a Yang Wood art, which was pretty far away from everything else she knows. So Yellow is perhaps where you're free to experiment and try things out, but as you move through Green you settle down. Of course, the cultivators that Ling Qi compares herself to are ones who are already more or less set in their 'path'...