Ah I see you've become a true white collar Calgarian.  I do wonder if you would have argued in the same manner 6-7 years ago.
I'm not going to choose an explicit for or against side, but only to issue a few points.
It's been said already, but those pipelines will spill at some point.  Whether that risk is worth taking is the true question.  It is impossible to claim that there will be no direct environmental disbenefits.  The product being moved is also more abrasive than what most pipelines currently carry.  The Northern Gateway would also see condensate being piped the other direction in a parallel line.  Anyway, I'm not here or able to get into exact technical details.
But you aren't exactly presenting your points with the best of rationality.
I think the ferry sinking was pilot error wasn't it? I'm pretty sure the
 captain was found to be at fault, which no one was surprised about as
he was reportedly a fuck-up
So what if the ferry crash was due to a captain fucking up?  Aren't future captains susceptible to the same things, especially seeing as how they will be navigating super tankers?  Maybe nothing will ever happen, maybe something will.
Why is expanding our energy production capacity a bad thing???
On the converse is it necessarily a good thing?  I would say that on the short-term and without really looking at it from a systems point of view then yes, this is a good thing.  More money in Albertans' and Canadians' pockets (theoretically) so they can go and spend and consume more.  That is, afterall, the sign of a positive and successful economy...
Then there is that little issue of GHGs.  I mean it isn't perhaps the soup du jour in Alberta to "believe" in  such things, but that doesn't mean that the contribution isn't there globally - hence, making this more than a NA or even Chinese problem.  Not too mention entrenching society on a whole on a further oil path dependency, or at least that of NA.  What is it, 5% and rising of Canada's 2% contribution?  Yeah, it isn't much.  Find me another natural single concentrated source that can display that same amount - not industry or electricity generation method.  I'm not sure that one exists.
That being said, Calgary and Alberta, indeed Canada is increasingly becoming a one trick pony.  Sure we are reaping the economic benefits now.  What happens when oil runs out?  And it will:  130 billion barrels currently recoverable in the Athabasca sands. World currently uses ca. 80 million a day.  Math doesn't look pretty.  (Very simplified analysis.)  And I think anyone that understands markets knows that oil doesn't have to literally run out, to "run out."  Then we will be left with a society that eschewed knowledge and innovation for easy resource money, and easy it is.  What happens too once Suncor and Syncrude and CNRL and company start seeing the economic viability of the projects go down, taking the economy with it and then not being able to further pay into, what is likely already a lackluster remediation fund.  Oh, the cost of remediation.  See Giant Mine, NWT or Faro Mine, Yukon.  Their figures aren't and won't be pretty.  The oil sands mines will make that look like peanuts.
While we are at it, have you ever had the pleasure of boating on a Suncor tailings pond?  I, the lucky guy I am, have.
The pipelines will only reinforce and catalyze all this - this basically massive science experiment where we haven't been able to evaluated the consequences properly in relation to the speed of development.
There are points against it. You've made a few. Even for a second
seriously believing that it's not going to happen, though, is not sense.
 It's the opposite of sense. It's going to happen. Delaying the
inevitable is contrary to everyone's interests.
The above may all be well and good.  Some points for here, some points against there.  However, this comment is really where I think you should know better, and I make no reservations saying that.
It's a similar route the Conservative Gov is currently taking too, using a politics of power to say what is right or wrong.  Last time I checked Canada is a democracy, one where deliberation and discourse is encouraged.  While the 18 month process does seem excessive, somehow attributing it to the fact that everyone's grandma and their dog can speak to an issue that the supposedly have no stake in as being fallacious, points to a foregone conclusion and the use of the process as rationalization.
While this is a bit of an aside, Canada is increasingly losing its world reputation as a country of relative progress, these pipelines included.  Essentially, the world, or at least Europe has taken note and I don't think it's necessarily something to be proud of.  At least not for myself as a Canadian.
Finally, using that as a segue into the main point.  How is this in everyone's interest?  I couldn't give one bit of a fuck if those pipelines are built.  I personally don't think it benefits me at all.  In fact, summarizing the points above, I think of it more as a disbenefit for me.  I don't (not anymore and never will again) work in the oil industry and I don't see a development path based on it being one that is beneficial in the future.  Instead, we are just delaying our inevitable problems or being overly optimistic that somehow it will all work itself out.
Why shouldn't those processes be allowed to slow down the development?  Why should oil stay cheap.  It already is too cheap and "allowed" us in some respect to "beat" the system as we had known it in the previous oh, since humanity.  Instead we built shitty cities, infrastructure, and indeed an entire economy based on cheap, finite energy.
Here is an idea, and this isn't aimed at anyone directly.  Take you bike.  Forget your 3000 sq ft house in the suburbs.  Forget about an SUV.  Don't buy the latest iPhone.  You want to get off foreign oil - consume less.  Standard of living does not equal Quality of Life.
On that final note, that is why I actually am not against the pipeline either.  The companies are only doing what the consumer demands.  They see it as profits and use their muscle to their advantage, but the consumer is the one that is providing the reasoning for it in the first place.  I would also rather see money put toward alternatives, but charity is not a privates mandate.  You need to pay for what you want.