Ok, well, there's a lot to break down there, but I guess there's nothing to do but dive right in:
The process of buying Moon Gifts is different from buying Shadow Gifts is different from buying Wolf Gifts.
Moon Gifts aren't normally bought. They raise with your Auspice Renown. You cannot buy them above your Auspice Renown. In the event that they publish more Moon Gifts, there is a cost listed for them, but that's about it. You can't buy these, otherwise.
Shadow Gifts just need to be unlocked by a spirit in certain circumstances. Wolf Gifts are inherent to all werewolves and never need to be unlocked. It's not really that complicated.
If you are Rahu and buy Cunning Renown, you get a Cunning facet of any Shadow gift you have unlocked. What happens if you have no unlocked gifts? You get a wolf gift.
No. You can choose to get a wolf gift, or save the facet unlock until such time as you have a gift it can apply to. That's RAW, in the book. You're only forced to take a facet if you have an open Shadow gift that it could apply to, and even then it's not hard to do a little pre-planning to not back yourself into a corner.
If you are a Rahu and buy Purity Renown, you get your Moon Gift for free (which doesn't need to be unlocked). Then you ALSO get a Shadow Gift's purity facet, which I didn't know until recently and I've been playing werewolf 2e since it came out (and staffing it) and literally only one player has ever pointed out to me in the entire time I've been staffing it, so this is obviously not super widely known. (Again, unless you don't have an unlocked gift with an open purity facet, in which case wolf gift, unless you don't have any more wolf gifts, in which case...?)
Where have you been playing and/or staffing? Because the games I know off, off the top of my head, that ran Werewolf 2.0 were Eldritch (and @Coin and I most certainly ran it with these rules -- I even wrote a whole big thing) and Reno/Portland -- and I know for a fact that we're doing that there, too. So...
Once you get it down, it's not that hard. But if you've ever tried to explain it to a newbie to werewolf? You'll find a LOT of things that are unclear and hard for them to wrap their heads around, and a lot of fiddly little things it's easy to get wrong even as a veteran.
I've explained it to -- fifty? Sixty? It usually takes all of like four minutes, lol.
"There are three basic types of Gifts: Moon, Shadow, and Wolf. Wolf Gifts are things that are inherent to all werewolves, and you can just buy these normally with no additional hassle. Moon Gifts are unique to each phase of the moon that a werewolf can turn under, and have a Renown associated with them. You raise the Renown, this gift goes up. Shadow Gifts are the powers of Spirits, and have to be unlocked by a spirit before you're allowed to buy them."
"When you raise a Renown, you can get a facet in a Shadow Gift for that renown for free. If it's your Auspice Renown, it also raises your moon gift. You can always choose to put this on a wolf gift if you want, or if you don't have a Shadow gift this can apply to and don't want to put it on a wolf gift, you can save it until you do have a shadow gift this can work for."
The dice pools for gift lists are ALL OVER THE PLACE and require extremely broad investment in attributes, skills, and renown compared to, say, vampire Disciplines (where some clans can buy their entire suite of Clan Disciplines up to 5 with only minor investment into attributes and skills to perform very well - a Daeva with Brawl and Empathy does everything a Daeva is expected to do, Discipline-wise, very well. A Gangrel with Brawl and Animal Ken, similarly. Show me a werewolf who can buy two skills and be competent at their Tribe/Auspice gift lists and intended roles.
Not a bug, a feature, given how integrated Renown is to every other part of werewolf. It's why we put the brakes on it so hard.
You might say, "Okay, but you're not supposed to focus on a single gift list, you're supposed to focus on your Auspice's renown!" Uh, all right, but now you're spending a TON of XP on gift unlocks and way behind in effectiveness while still being more complex and having a more varied skill list requirement.
I would never say such a thing. Have you met my werewolf?
Werewolf gifts are needlessly complex and while what they DO is very cool, they could have been organized into straightforward 1-5 lists like Disciplines and done similarly well.
They're really not that complex. I honestly think that you're just overthinking them, especially since the brunt of your examples come from an apparent misunderstanding of how the facet unlocks work.