Before I get into ideas: Boosts are defined on page 62 of Fate Core (bottom of the page), and started on page 138, they go into the Four Outcomes ("Succeeding With Style" being what grants the boost), and then the main actions of a character.
Now, since we seem to agree on everything else, I'll work on the one point of "debate" that still remains:
In general, I don't like the idea of weapon breakage; a properly made sword, even one that isn't your father's Soldano blade, can't really be broken without taking the time to stick it into a vise and go at it with a hammer. Definitely opposed to aspects or Items of Power being broken; there's a reason they all get the "no breaking me without major plot" quality for free.
I'd personally like to leave the idea in place as it was a big deal for a couple of the schools (Eisenfaust and Daphan off the top of my head, but I recall seeing it in one or two more schools) and at least one type of Montaigne Puzzle Sword (it had a sword-breaker hammer if I remember correctly). I can see it as a good plot device to promote Aspects being changed, or even a story line to gain a new weapon or repair the old one. We see some epic tales like that already, so why not keep it?
Items of Power hit that grey area, as in 7th Sea, VERY few items were truly unbreakable. The unbreakable items were types of Syrneth artifacts, some other relics, and one type of Montaign Puzzle Sword. Different blades were tougher to break (Soldano blades, Pattern-welded swords, and Dracheneisen are the first I can name offhand), but they were breakable in the end. Since it required a Drama Die to do it, it was usually at a cost AND dramatically appropriate, so why not emulate it?
Perhaps we should toss it in as a Stunt to even be able to attempt it, and if it is an IoP or an Aspect, a Fate Point must be given to the character?
I can see an IoP breaking causing a potential Aspect change or even an in-game story to replace it, while an Aspect being "forced" to be changed can be attributed to the end of game minor milestone to simulate the broken weapon and how it impacts the character.
Just a thought, of course.
I'll start writing up the other stuff when I have the mentality to do it. Work has me doing a lot of report writing lately, and that's been making me unmotivated to stay at the computer any longer than I have to.