Alright so I've made up my mind to back the Brotherhood of Steel. Sure the leader is a fanatical blowhard who just exiled my best bro and hates my really cool ghoul and synth detective friends (and let's NOT get into what he and the rest of the brother think of my French girlfriend) but the Brotherhood is where my heart lies. Now here's my question to those of you who have completed the game before. How far can i run with the other factions before I have to commit to the Brotherhood?

The strategy guide says that there is a railway rifle available from the Big John Salvage Yard so I don't need to finish that quest line for the Railroad (in fact I'm thinking of just finishing the Randolph Safehouse quests to get the Killer Institute weave and bailing on them). Also once you complete a DIA cache mission does that automatically unlock ALL the marks of ballistic weave or do i have to do more? And how far can I go with the Institute before I betray them? Is it possible to get max affinity with Deacon and the Courser companion, get their perks and then destroy both the railroad and the institute and have them be ok with it/get their perks and then kill them when they refuse to be friends after destroying their factions? Or will I just have to say screw it and forget about them?

Also how do you get Danse's perk? I thought it was after the exile mission but when I talk to him again he acts as if I've done something naughty.

I know its a lot of questions but thanks for any/all answers.

Curie isn't really a synth.....her only objective was to find a cure to all of mankind's diseases and took over a brain-dead synth wiped of all Institute programming. Valentine is a gen one scrap pile the Institute couldn't care less about and obsessed with the memories and life of a pre-war detective.....they are very rare exceptions. Dense and all other synths are nothing more than weapons....their every thought and memory crafted to convince people they are human and that they should be accepted so that they may spy and cause great destruction........what the synth itself may think of this is largely irrelevant as their memories are usually wiped and don't contain intel that can harm the institute for the most part. Caring for a synth is exactly like caring for a rifle, this Onion article perfectly describes synth sympathizers: http://www.theonion.com/article/nra-visits-colorado-police-evidence-room-check-rif-51924

Exactly why I decided to join the Brotherhood of Steel. My question still stands. How much use can I make out of the other factions before I have to kill them? If it turns out I've already got all the marks of Ballistic weave in one go then ill just finish the six randolph safehouse quests and then blow them to kingdom come.

Also don't you compare caring for synths to caring for a rifle! *comforts rifle* "Shoosh shoosh its ok darling."

I got Deacon's loyalty perk which is pretty beast and since all he ever did along the way was try to lie to me and dupe me I didn't even feel bad when it was time to shoot him in the face.....and I still got to keep the perk!! That counts for something I think. You can do some side work for the Railroad but I rather not aid them. The minutemen don't matter as they follow you no matter what though Preston Garvey won't travel with me anymore because he's super pissed I didn't give the evacuation order at the Institute.....last thing I wanted was to allow enough to escape so they could regroup and rebuild...no thanks. But I still keep his loyalty perk so he can whine all day and all night for all I care. It's probably ok to work for the institute a bit before blowing them up as it usually involves hunting down synths so that's ok.