Yes, I picture some of these events as overlapping.
This is again an issue of...we need to know what we are trying to show (timing-wise), even if the exact chronology isn't fully communicated to the audience.
Some of those things certainly start prior to year 5. So, for instance, the Noldor will have begun to explore their immediate surroundings right away, and are no doubt venturing further and further into Beleriand as time goes on. Also, I don't think that Galadriel needs to wait for the reconciliation of the two camps to visit Doriath, though Angrod does. (If only because Galadriel isn't going to say much and her mission as ambassador functionally aborts before she accomplishes anything.)
So: Maedhros' recovery: part of Year 5
Scouts exploring Beleriand: Years 2-7 (ongoing)
Galadriel travelling to Doriath: Year 4
Angrod travelling to Doriath: Year 6
Noldor establish and claim realms: Year 7
Fingolfin acclaimed as High King: Year 5 (I recognize this particular item is contentious)
I probably wasn't going to assign such a lengthy time to Maedhros' recovery. I do agree that he is in very bad shape (starved/emaciated/bed-ridden) when he arrives, and on top of that, he just got his hand hacked off. I have always pictured Fingon and Thorondor delivering him directly to the Fëanorean camp for his healing and recovery, but obviously arguments could be made for bringing him back to Fingolfin's camp initially and then returning him to the Fëanoreans.
Tolkien gave the Ringbearers a couple of weeks to recover after their time in Mordor. We can certainly give Maedhros longer than that. But after, say, 2 months, I would expect him to be up and about. Not at full strength, and not immediately leaping into governing, but able to start doing things again. He would work through Maglor at first, I agree, and he has to learn to function one-handed, which can't be much fun. So, early recuperation is focused on physical recovery (needing assistance getting dressed, eating food and keeping it down, healing his stump, staying in bed the majority of each day and only the lightest effort towards putting out fires and reasserting Maglor's authority) He'd see his own brothers and Fingon (family) when they come to his sickroom, but not the general population and certainly nothing in his role as leader of the Fëanoreans. This is the phase I would think is something in the 8 weeks range (obviously, open to discussion). Then, as he regains his strength and isn't perpetually exhausted, he'd work on figuring out how to be leader again and trying to regain functionality. Now he has to learn how to do day-to-day tasks one-handed, (I don't mean relearn how to ride a horse and use a sword -- save those skills for later). It's at this point that he'd begin exerting more control (still through Maglor), and start taking steps to reconcile the two camps. He would go 'out and about' in his own camp, and be seen by the Fëanoreans in general, not just immediate family (but still no visits to Fingolfin's camp.) I'm not sure how long this 'planning' stage would take, but...again...some time passes. When he's presentable, there would be some formal gesture of reconciliation - offering horses, livestock, lembas, but also going so far as to apologize for the burning of the ships in addition to publicly thanking Fingon for his rescue. This would happen as part of a planned formal meeting of both Hosts; maybe not everyone is present, but it is a large public event. I picture him abdicating his claim to the High Kingship at this time, so we'd have to wait until everything is in place for this to happen. I would imagine this would happen 6-9 months after his rescue (again, negotiable). I feel if they wait too long, they lose some of the impetus of reacting to Fingon's rescue of Maedhros. Maedhros isn't going to want to wait too long. He doesn't have to be 100% back to health to do that. He could still be working on his stamina and his one-handed skills over the coming years. Healed enough to be presentable and not limping around or having to sit down because he gets winded instantly and drink only broth at meals. He should still be a bit gaunt, just...not at death's door any longer. 'Stable enough not to embarrass himself' isn't quite the same thing as 'healed'.
We do have a bit of an issue trying to squeeze everything into Episode 1. We could bump Maedhros' rescue back to episode 2, but I don't think this gains us much. I also think the Hosts were counting on a dramatic Season opener, and 'uncomfortably awkward camps and language learning' probably isn't what they had in mind. So, we can keep Maedhros' rescue at the end of Episode 1, and then show his recovery in Episode 3. I propose using Episode 2 to be Sindar-centric, so we would show both Galadriel's time in Doriath and Círdan's time with the Noldor (as well as any other Sindar-centric stories we want to tell) to emphasize the different perspectives while allowing us to show some pre-Year-5 events in Episode 2.
So...I would propose breaking it down this way.
Episode 1: Years 2-5, Noldor perspective
Episode 2: Years 2-5, Sindar perspective
Episode 3: Years 5-6: Reconcile the Feud between the 2 camps, send Angrod to Doriath
Episode 4: Year 6-7: Angrod returns from Doriath, Noldor claim their realms, Caranthir and Angrod clash
Episode 5: Year 20: Mereth Aderthad
To do this, we would need to show Galadriel leaving for Doriath and returning from Doriath in Episode 1, but show her actual time in Doriath in Episode 2. Since she is so starkly changed, I think introducing a bit of mystery/anticipation there is not a bad thing. I'm also a bit fuzzy on how Angrod's trip will tie into the other storylines, so whether that's the end of Episode 3 or the beginning of Episode 4 (or both) isn't really an issue to me right now. The important part be that he leave after having witnessed the reconciliation of the camps, and that he preferably be sent by High King Fingolfin.
I am also fine with separating the abdication of Maedhros from the formal crowning of Fingolfin; they don't have to be the same event. It was just important to me that Maedhros be the one making that decision and preemptively abdicating, not waiting for the Noldor to say, 'Who's in charge? I guess it must be Fingolfin because no one wants to follow the Fëanoreans any more.' It's the kind of situation where if we build up Maedhros' efforts to reconcile, and we know he's going to formally apologize, and everyone is geared up for this public event....and then he abdicates...that's a bit of a shocker (or should be), and we should let the Noldor react to that. They don't have to have a coronation for Fingolfin on the spot, but it could be (for instance) an episode tag, or the opening of the next episode.
