Indo-European: what I'd like to know more about

Andronovo chariot warriors

What would I wish we could know more about in terms of archaeogenetics and archaeology and linguistics?  The following is my early wishlist for understanding better what was going on during the formation and spread of indo-european cultures.

• Better understanding of Sredni Stog genetics.  More sampling needed.
• Better understanding of the specific genetic and archaeological relationship between Sredni Stog and Corded Ware, as well as between Sredni Stog and Yamnaya and Yamnaya and Corded Ware.  My supposition, based on a pretty broad-brush archaeological glance is that Sredni Stog II and Khvalynsk (and Repin) all had contacts, at least, even though they maintained some cultural and genetic distinctiveness, and all spoke dialects of Proto-Indo-European.  When Yamnaya formed and spread to cover the entire steppe, it came from Repin and Khvalynsk in the northeasterly portion of the territory, and while it absorbed some Sredni Stog, it also largely displaced Sredni Stog, at least with regards to Y-DNA lineages, which upon displacement, went north and west and became Corded Ware under the influence of the natives upon which it largely superimposed itself.  But this needs more genetic data to be confirmed.
• In addition to this, while the displacement of Sredni Stog which led to the Middle Dnieper and Corded Ware culture by the Yamnaya expansion makes a lot of sense; it explains the Y-DNA split, it is a good match archaeologically (it's long been believed by many that the iconic Corded Ware ceramics, there is a not insignificant temporal gap between the Yamnaya overwhelming Sredni Stog and the formation of the Corded Ware.  And in the gap we have to explain the Globular Amphora culture, which doesn't really seem to be too similar to either Sredni Stog or Corded Ware, necessarily, but geographically it has to be explained somehow.  In any case, that temporal gap depends on a lot of dating controversy.  Did the Yamnaya form shortly prior to 3,000 BC (from the much longer-lived Repin culture) or did it form earlier?  What's the timing of it's expansion?  I don't know, and I think that that's still an area where more data is needed.  (The Corded Ware origin is dated a bit more precisely at shortly later than 3,000 BC.)
• Much better understanding of the origin of the Anatolians and their relationship with the steppe.  Much more genetic sampling needed.  Did they, in fact, come from the early Suvarovo expansion from the steppes into the Balkans, like I think they did?
• Much better understanding of the late Neolithic and early Bronze Age cultural formations, especially in the Europe west of the steppes.  I think it's a bit clearer on the steppes (although I'd like to see some better evidence for the population replacement that I think happened as derived Fatyanovo and Abeshevo, i.e. post Corded Ware, pushed the Catacomb culture out of the steppes to become the core of the paleo-Balkan Indo-European languages, including Greek, Armenian, Phrygian, Thracian, Illyrean, etc.  But the whole evolution of Usatovo into eastern Bell Beaker, Tumulus, Unetice, etc. that later emerged as Urnfield, Nordic Bronze Age, etc. is still a bit handwavey, at least in my mind.