I SUDDENLY FOUND MYSELF KILLING MY FRIENDS ON BUNKER HILL WHILE HELPING THE INSTITUTE . MAY I FINISH THE QUESTS FROM THE INSTITUTE AND THEN GO BACK AND FOR THE QUESTS FOR THE OTHER FACTIONS ?

Not in a single playthrough

^That's a good thing, but is it possible to play parts of other factions before final decision? (As far as I know it should be possible to play few quest for more than one faction)

NOOOO YOU CANT FINISH ALL FACTIONS MAIN QUEST THEY'LL GET PISSED OF AT YOU FOR DOING CERTAIN THINGS IN ANOTHER FACTION!
..........HELP I CANT STOP SCREAMING NOW!!

NO! IT IS NOT POSSIBLE TO DO A CHARACTER THAT DOES ALL THE FACTIONS LIKE YOU CAN IN THE ELDER SCROLLS!! I THINK THIS IS A GOOD THING!! RAAAAAAGGGG!!!

SEE OP THATS A NO GO ON THE FACTIONS THING GOOD NIGHT AND HAVE A PLEASENT TOMORROW!!

Lay off the all-caps guys, it makes me very grumpy.

Forum rules -

fine........

Message received. I'll stop with the all-caps.

In Fallout New Vegas (at least to a limited extent) you could mitigate the quests which were going to piss off the other factions. Not all the time but sometimes. For instance, the NCR sends you to kill the BoS and you basically say no that they can fight with the NCR when the balloon goes up and they say OK. Doesn't work for House but then he was OK with it once I killed him.

I would like more of those options. Faction A quest: Kill faction B? No, still want me as a teammate? If so then let's NOT kill faction B. If not, see ya. Normally a "lone survivor" or "courier" or "vault dweller" etc. wouldn't have that kind of pull but you are the protagonist with the ability to get ridiculously strong (and the power to redo your failures) so being able to convince the factions to get along doesn't seem so unreasonable.

You can join all of them but not progress past certain point in their stories before becoming enemy of others.

Wud be nice if it wud be possibile to influence em to try and work out stuff without killing eachother though story wise realisticly you wud only hold high enough ranks/power within certain factions post main game for that to work(except Minuteman which you are leading from the start ofocurse, but than again Minuteman dont force you to go against any other faction if you desire so)

But yeah i wud love to see more options with than.

The answer to the subject is "Yes."

The answer to your question in the post is "No."

You can join them all but you can't complete major questlines for all of them in a single playthrough.

I did the Battle of Bunker Hill as friends of both Railroad and Institute and... spoilery...

Spoilers follow...

If you want to join all the factions, you're forced to side with the minutemen. They are the only faction that won't require you to become enemies with all the other factions. However, I noticed the other factions stop talking to you after you get to a certain point in the minutemen storyline. This might be a glitch, but I'm unable to talk to Elder Maxon or Teagan.

I agree and disagree with everyone above. I like how you can't join all the factions, like you couldn't join all the houses in TES IIII Morrowind, but I don't think that excuses the lack of guilds. Yes, you get 4 factions, but they're all tied into the main quest. I'd prefer if you get those 4 factions for the main quest, and have some unrelated factions to progress through (like the guilds in TES). I wish we could join, for example, a group of hitmen, the outcasts, enclave remnants (just examples)...or whatever that have isolated stories separate from the main quest line.

How far can you go questwise in all factions before you hit the point on no return?

I know for the Brotherhood you can go all the way up to dealing with Danse - but if you accept the next one it will lock you out of the Railroad.

I'm not sure for the others.

Depending on what you mean by joining the other factions and requiring you to become enemies, this isn't true. You can join all factions and do their storyline quests up to a quest called Mass Fusion. I'm not including quests that directly involve you wiping out a faction or quests you receive from directly shooting up a faction on purpose (that is e.g., you decide to randomly go to a faction HQ and shoot people up). Doing those sorts of things prematurely makes you enemies with a faction. At Mass Fusion, you are forced to either make the Institute or the BoS be hostile towards you. At this point, you can branch out from a single save and get any ending you want. Getting the Minutemen ending requires you to become enemies with the Institute. And becoming enemies with the Brotherhood to take them down is optional. You could technically just never make the Institute hostile at the cost of not getting an ending, but that's achievable with every faction.

TL;DR You can join all 4 factions and do their quests up to Mass Fusion without being kicked out, regardless of which ending you're aiming for.