I think the thing that a lot of teachers in these conversations don't seem to appreciate about other vocations is they too operate in high-stress environments. And with those, you don't have the opportunity for 25% of the year off with no professional responsibilities during that time.
I don't think it is something you need to justify, though. I think an answer along the lines of, "Yes, I'm very fortunate to have a job that allows me to enjoy such a great work-life balance" would satiate a lot of criticism. In my opinion, the public isn't antagonistic towards teachers and their benefits; however, they are a little frustrated when these perks that would be unsustainable in the private sector go under appreciated.
This is a disingenuous line of reasoning, IMO. A teacher's life is very similar to a student's - and all of us used to be students. For 75% of the year, you are at the school for a minimum of 6.75 hours per day (with an hour break for lunch). Then you go home and have homework some days and not on other days.
While as students we didn't exactly follow a teacher's schedule, we operated in the same environment with similar enough lifestyles to provide a very strong frame of reference. I think all of us know what it is like to be a teacher more than say what it's like to be a fireman, or a cop, or a pilot, or work shift work, etc.
Okay, so you've contributed $200,000 to your pension. That's great, but not unique. Anybody who plans to retire needs to save. What is unique for teachers versus most in the private sector is your pension is guaranteed by the taxpayers. It will never go down. You never need to worry about a pool of money running out, or the economy tanking and you have to take a job at Wal-Mart. A predictable, very liveable cheque will be automatically deposited into your account every month from the day you start teaching until the day you die. I think you should appreciate that for just how insane it is in today's world - I mean there's a reason not every company has a pension plan and of the ones that do most are not guaranteed.
As for the time off - it's hard to feel too bad for teachers that their time off is fixed. If I could choose to have 25% of the year off - with pay and no responsibilities - I'd take a couple months of in July and August when the weather is at its absolute best. I'd take a few weeks off around Christmas because I like to snowboard and it's a fun time of year to have off with all that's going on. Probably take another 10 days in the Spring to take a little vacation or ski some more. Then I'd sprinkle a few days here and there throughout the year to balance it all out. You literally have the best days of the year off, so it's hardly a cross to bear that you don't get to choose them - they're the ones you'd choose anyway!
Did I read it wrong that you don't think it's ideal to reach the top of the pay scale after 11 years?! That's some very strange logic. It's a dramatic line from base pay straight to the top in a very short span of time - a few may do that in the private sector, but it's far from the norm and incredible (for teachers).
And your raise in September isn't "under attack" by the premier. It may be under review, but the way you describe it adds a negative spin that isn't fair. Have you been to the "Layoffs in the Oilfield" thread? Are you aware our province is going through something that is dramatically affecting the lives of Albertans. I would think as a taxpayer and citizen of this province you'd voluntarily offer to forgo the 2% raise in September if it isn't in the budget. I mean, that's how the world normally works. If something can no longer be afforded, then we need to review it. Very strange attitude you have on that, IMO.
Maybe pick it up in July and August - I imagine you'll have some free time then.

(I don't mean that to sound as bad as it does...just a playful jab.)
Anyway, just so everybody is clear, my interest in this is because I see teaching as such a great career. I think the negatives of it are wildly overblown and the positive aspects of it are undersold.