and curiously enough you agreed with me here, Zyraen, yet you still persist...
Actually I agreed with you because I was actually listening to you in conversation ^^;; but it seems you weren't exactly listening to what I had to tell you.
Firstly, we shouldn't meet him at all in the place we are supposed to meet him. He shouldn't be there at all
Well Finarfin does show up at Alqualonde (eventually) and he is also the only one isolated at the end of it, for a possible approach. I don't see how it would be possible to approach anyone else in that scenario, given that practically everyone survived AND continued to stay with the main host.
I dislike the idea of having father&son in my party, for some reason, plus having a romance with the son while the father is standing few meters to the left
This you didn't mention this in conversation

Its a cute point, and probably quite valid for humans, but I don't think Elves really mind that much. Maybe make Finrod unromanceable around his dad? lol. Or a "chaste" romance

I can see that with the still-Amarie Finrod lol. Actually I like the idea of having close friends/relations in the same party (like Illuvi-Imari, Finarfin-Finrod, Beleg-Turin, and in my original concept, Gharin-Khorin) It makes for far more interesting banters than
BG2, with plenty of character development.
* Finarfin, compared to other NPCs, simply belongs to another league. We can't have Feanaro or Fingolfin in the party, so why have him?
Unlike Vampires in VtM, there doesn't seem to be an explicit mention that elves are powerful based on Generation. Certainly we also do know that Finrod was a far cry waaaay above Orodreth Angrod Aegnor and Galadriel. Feanor and Fingolfin have more than demonstrated their party-unbalancing abilities in the storyline itself ; Finarfin has never. Besides, I don't intend to make him Mary-Sueish, and a pure magic user has very little to crow about Silmarillion in terms of long-lived usefulness.
I understand your thoughts on the other characters, and I think you neglected to mention my notes - that Maglor was fairly alive and having an ACTIVE part in history, not to mention AGAINST the party ; Aredhel really was a nobody and I'm not likely to create a scenario out of a non-event to get her ; Ereinon/Gil-galad was alive and had a concurrent role of his own to play (and I do dislike him lol)
* Going with you at the given point is OC for Finarfin, imho
You never even asked nor bothered to listen if I would mention, how I was going to make him join. You think it would be easy ? Not knowing anything about the plan, how would you say its OC? And given how undefined he is as a character, how would we know he's OC?
Simply put, Finarfin has too many reasons to NOT be there (and curiously enough you agreed with me here, Zyraen, yet you still persist... ).
The only thing I saw and acnknowledged is his personality, and that can be worked around using a hard-to-join and joins-for-greater-good approach. The other reason is that he does NOT die (unlike the other timestream joinables), but similar (and more importantly) as compared to all of them, he does NOT have ANY significant active role to play in Silmarillion thereafter.
Some characters are just meant to be secondary ones... I would rather develop his other sons; they are indeed underdeveloped...
Lol you're absolutely right. That would apply to Beleg, Mablung, Finarfin, and also to Maglor Caranthir Amrod Amras, and Finarfin's sons Orodreth Angrod Aegnor. Finarfin is just another character to choose out of all these

there's no particular reason aye/nay with respect to this line of logic.
That being said, I'm quite OK with removing Finarfin without replacing him. A Pure Mage is really not necessary for Silmarillion, and might be a huge liability in practice. Alternatively I might make Kyra a Sorceress, but frankly I think she'd be ... REALLY Mary-sueish (those with forum access know why)