I don’t think we are able to assess whether it is a good setup yet overall. We’d have to look back with hindsight over the whole story. My own opinion (which is no more than that) is that as of now, I feel that most storylines are established enough to launch into a next phase in S2.
For example, we know that Sauron has been trying to ‘heal’ Middle-earth and that Adar rebelled against whatever he was trying to do in the North and usurped Sauron’s plan for Mordor. We know that Mordor is established as a home for Orcs. We know that Numenor is a civilisation that projects power and greatness but is culturally entering into a bad place. We know that the people who used to live in what is now Mordor have evacuated to the mouths of the Anduin with some Numenoreans, setting up proto-Gondor and also the interactions between Numenor and humans in Middle-earth. We know that we leave Durin and Disa heading down a dark road, being possessive of Mithril, setting up the next phase of their story. We know that Nori and the Stranger are off to Rhun, which is already populated by Sauron-worshippers.
The Elf storyline is the one least set up for me I feel, and so I hope they will be filling this in in S2. If the making of the other Rings of Power are a key part of S2, leading up to the forging of The One Ring, then I expect to see a lot more of the Elves of Lindon and Eregion in S2.
I also see S1 as the ‘Galadriel’ story - this was the character who we spent most time with and showed the most growth (I know not everyone sees her this way). She still has a ways to go and I expect that she will still be a major character throughout all seasons. I think they have set up S2 to be Sauron’s story, which may well include starting the season at a time prior to the start of S1 and this may be how we get to the Annatar story and how Sauron got on a raft disguised as Halbrand).
So far I don’t see any radical departures from Tolkien’s writings on the Second Age as far as these story setups go apart from aligning the times of the making of the RoP and the fall of Numenor (I have no issue at all with that decision).
The story of Mithril I agree seems problematic and I’m personally not keen on the story of the roots of the Hithaeglir, but Elrond also sees it that way so I am taking a ‘wait and see’ approach. Mithril, as Tolkien wrote it, is clearly very special and has qualities that no other metal has - and Sauron ‘coveted’ it, we are told. I see the show as trying to explore what in particular is special about it.