From what I heard the dialouges and most cutscenes are in FP too, at elast that's what the people say who saw the demo behind closed doors.

I read on reddit that the dialog will use 3rd person view like in deus ex. Not sure how accurate the source is.

Personally I have no problem whatever the dialog camera is, as long as the dialog itself is good.

What I'm concerned with is when I want to role play and no dialog option fits my character. After all this is a game where you create your own character. They can't possibly cover everything.

Same here. After 25 years of FPS's, a few people suddenly "can't play them" just for Cyberpunk 2077 (yet seemed to have no problems with Deus Ex?...)

The deal is when they prefer 3rd person view, or if they find 1st person view to be nauseating. I used to not be able to play fps game until I'm 20+ because I'll get bad headaches

Well, I think that we need to look at actual gameplay before making any decisions. Maybe, just maybe, they made game with First-Person Perspective because Thirf-Person Perspective didn't worked well with new game. For example, city is very crowded in some areas and you can "lose" your character at some point or it is just uncomfortable. After all, they already had all tools for TPP game from Witcher 3 and they decided to dump all this to develop new FPP tools.

Anyway, I won't make any decisions until they show actual gameplay.

Now that I think about it... how is it usually done in first-person? E.g. in Half-life 1-2 you, the protagonist, were completely mute. People just kept talking to you and you never said anything (even though apparently the others felt you did).

Do the games move to 3rd person because they want to make clear who is talking, at all times? So you start hearing some voice and look around you trying to figure out who is talking to you, only then to realize that oh it is "me" who is talking.

Then again, in the first Deus Ex it took me awhile to realize "Ok that dude with sunglasses, that is apparently me in these conversations.".

Which makes me incidentally realise that I like first person perspective and top-down views (isometric, or otherwise), but not over-the-shoulder, except for pure brawling games à la Arkham or Mordor. I just don't like staring at a character's back for hours. So.... it's positive news to me, I guess.

That's the core of the issue for some I think xD

Hopefully, they will have an FOV slider. I can find FPP games nauseating if the FOV doesn't fit my monitor size or placement distance (usually the default is based on the typical size and distance of a tellie from a sofa, console style). I would have hoped that an FOV slider in an FPP would be standard practise, but many game developers I thought should have learned by now have failed me in the past.

2077 Frames Per Second?

Well I can understand motion sickness though I'm pretty sure CDPR will use common mitigations like, adjustable FOV, ability to tone back or disable head-bob, etc. TPP often just replaces one set of issues with another though (eg, cures first person motion sickness, but then introduces a feeling of "disconnect" / lowered sense of immersion, camera being too close or especially "off-sided" camera views or "camera jumping around in narrow corridors", etc, can feel even more disorienting). Example of absolutely horrendous nausea inducing camera shake in popular TPP game.

But when you look at their profiles, half the people complaining "I can't play FPS's" on Steam forums have like everything from Doom, Dishonored, Bioshock, Deus Ex Human Revolution, Wolfenstein TNO, going all the way to Half Life 2 in their collections, and I'm left wondering - "so what's changed only now?"...

Have they actually played those games, or do they just own them? Those are very different things.

My only problem is that I suck at them. :-p

There can be a number of reasons.
Putting aside those who get sick from playing them it could be:
-They suck at them (which can also applied to other gameplay elements, I'm worried about the driving might be mandetory for example)
-They simply don't like them due to personal preference
-They aren't used to playing them and are worried it might be too fast paced for them from what they've seen from other FP games
-They could be worried the story-experience might suffer (in my case for example I can't get invested into a character I don't see in cutscenes an dialouges and I don't get the feeling of better immersion from it because it lacks other senses than vision)
-Since the game has a character creation, they might want to see the character they created and its changed look (important cutscenes only doesn't work since it would probably still skip quite a few changes)

And since a huge part of the CDPR Fanbase was built on a TP-RPG an unusual high percentage of people with one or multiple of these issues was looking forward to CP2077.