I must say that NV is the best RPG I have played in years. It captures the feeling of being on the bleeding edge of events while still being believable. For the most part the quests are well written. I couldn't even manage a single play though for Fallout 3 because I found the quest were so lackluster, and pure sandbox gets boring for me fairly quick.

Here is my question that I could perhaps answer for myself by playing though, but I would rather not spoil my first playthough if I can.

Is the man quest line flexible enough that I can change my mind about Mr House and not get forced into an ending that breaks my character?

I have played up to the end of the Omerita family quests and thin seems to be the lock in point of the game. Before this, Mr House seemed the the best of the worst among choices for my female character. After all he had the foresight to predict the nuclear attack and save New Vegas and he also seemed the least plagued by ideologies. On the other hand he may be a machine and uses robotic soldiers.

After the Omerita family situation was diffused Mr Houses true personality seems to come out, using the R word (Regime) and asking my character to wipe out the BoS.

Is the questline linear after this point or do I have some room to maneuver ? (Spoiler free if possible)

well obviously if you wipe out bos you cant work for them so thats one option youd lose.i think your pretty much at the point where your side is chosen but maybe not.did you speak to yes man yet

If you want to keep working with House then sadly yes, you've got to wipe out the BoS. If you haven't alienated the NCR and/or the Legion yet you're free to switch your allegiance though, and even if they hate you there's always Yes-Man, who'll always work with you no matter what and kinda lets you do what you like. So yes, you're free to change your mind about House.

There are two quests which will eventually pop-up if you continue to work for House: They're called 'Don't tread on the Bear' and 'Beware the Wrath of Caesar.' Basically these are your last warnings. Until you are given these warnings, you can switch sides at any point (unless one of the factions is hostile to you.)

Also, Yes Man will always accept you

If you're pro-BoS, there's essentially only one way to have another option than the one House gives you - and it can't be done while supporting House. And then, even if you're supporting a faction that has the option, the path to be able to take/do the option is fairly specific & somewhat easy for players to lock themselves out of without foreknowledge. I can't say more without spoiling the path for you. Suffice to say the BoS are not given much to be happy about in NV....imo.

And yes, House/Legion/NCR all have those "Don't Tread On/Beware" warning msg. points if you continue to work for a faction one of them dislikes. If you receive such a quest/msg and want to be able to change your mind, immediately stop progressing in any quests (if it's Don't Tread on the Bear, stop any Legion-support quests) because the next one or two completions will cause you to be locked out of the protesting faction.