yup. But it buts a +2 on the guy, instead of a +4 (for declaration + maneuver).  as a GM, I only use declaration+maneuver to describe offscreen stuff to my overly rules-lawyering gamers:

Me "It appears the guy was killed in one blow"
player "How is that even possible? That's like 30 shifts of power with a tire iron."
me "Um, a butt-ton of declarations and maneuvers. Moving on."

I've mechanically limited my players to receiving or spending at most 2 fate points per compel-ing circumstance, due to just this.  One of my players originally made a character that was ALL about fighting evil, and wanted 7 fate points every time the group did exactly what it was going to do: go kill the baddie. So I spouted some BS about how I thought the book only allowed me to give up to 2 fate points, and stuck with it.  We changed his 5 other aspects to reflect more interesting parts of his character, and discussed how a compel has to be sort of bad for the character.

What I've learned to watch out for is things like "protective warrior" coupled with "i get angry when innocents are threatened", as it can create a kind of free invocation:  "hey i want try protect these people, here's a fate point. now give it back because i am angry about it!"

Interestingly enough, one of my characters has the opposite: a desire to strike down evil, plus a desire to protect others.  So when these conflict, she could end up paying to ignore a compel (going for the evil dude) to get a compel (protect others).  since that's silly, i always compel her to save people first, as that's her high concept.  So she has to go against that if she wants to smite the enemy instead.

Sometimes, it works out to her benefit, and she gets two fate points for smiting the enemy to protect the innocent. Often, she gets these (despite it being exactly what the group was going to do, and thus not really a negative to her) because she does so without regard to the situation... she'll slay a demon in front of a kid without really thinking about the consequences. To her credit, she almost always dishes these points right back into smiting the thing.

I should add that until recently, I had two player characters with that power. I tried to compel one of them each session, both if i could.  But sometimes a session was too busy for it, and i just compelled whatever was appropriate.

A zone block affects everyone, friend or foe.  The only problem with maneuvers is that then you need tags, and technically that means one "free tag" perhaps and then fate points should be invoked..  of course as a GM you could compel falls (offering fate points, that then require fate points to buy out of), which could indeed be very fun.

the problem with a block is that technically, one person breaking it should break it for all, which is kinda lame when the floor is iced.  So tags might actually be better here.

(For the record, I don't consider this "arguing", just.. er... discussing?)

I'm a little surprised it hasn't come up: it's the ultimate plot device power.  "You know this kid will die. Only you know it. Here's a fate point."

I like to give other PCs fate points to not believe my cassandra's tears players.  not really in the rules but it keeps them from just going "okay no one else does, but we'll listen to you!"

which has ended with one player screaming (as her character) "I'm not crazy!"

good times.

This seems like something I wouldn't allow simply because the declarations aren't really in the spirit of a declaration. Declarations are so easy because they are supposed to add flavor and color to the world, thus making the job of GM easier. These declarations don't really add flavor nor do they make my job easier.

Yeah, sorry, I was trying to give quick declarations but more examples. Technically, a declaration is any skill used in a knowledge-type way that could be done instantly (as a free action).  Each attacker could have declared "I use my fists vs his fists to size up his weaknesses, to help us set up a coordinated attack against him" and then maneuvered for "surrounded in a concerted coordinated attack".  Then the last person tags everything.  While, mechanically, this represents one person attacking, narratively it represents a bunch of guys working together (one swinging at you to tie up your hands, another kicking you so you try to block with your feet, while the guy behind you kidney shots you) to inflict major damage.

I see your point about why declarations are easy, but I see this as just as viable (and thus acceptable) of a form of play as each person attacking independently, and nickel and dime-ing the guy to death.  Roll-wise, it's about the same (they're rolling opposed rolls for all these declarations and maneuvers), but at least I'm tracking damage less often! It also represents how in a fight like that, you might take a lot of little hits, but only a few really seem to matter.

The line about blocking all actions versus one target or one type of actions versus all targets is straight out of the block section for YS, but I don't have the book on me ATM to post it for you.

My point about breaking magic to block is that literally ANY skill would work... you could say "I want to shake this fog off with endurance, discipline, conviction, lore (to understand it), scholarship (to mentally comprehend how your mind is being affected), athletics (i do a fe jumping jacks to clear my head)... literally ANY skill would work. So your scholar with a stunt in forensic science could roll like a +7 base by reciting the parts of the human body to shake it off... and so on.