Is the yahoo screenplay critiquing service any good?

I don't think that's a Yahoo service, 305, it's a page advertising various editing services.

Ask yourself: how have these editors proven themselves to be worth their fees?

It's also worth remembering that you've been given some very good advice in your own thread in SYW, which you have repeatedly argued against: would paying for such advice make you any more likely to consider it?

Format's pretty easy. You can find the margins and indentation and use them in word processing (I have them--on the other computer) or download the free-and-legal Celtx formatting program, which is not bad at all.

Format's the simple part of writing a good screenplay.

Maryn, who lurks screenwriting boards

Edit, borrowed with permission from an online friend who sells his screenplays:

You can use formatting software, but you do not have to. Any word processing program can produce a perfectly formatted screenplay.

The font is always, ALWAYS, Courier New (or some other form of Courier), 12pt.

The margins are as follows (from the left side of the paper):

ACTION ELEMENT: Between 1.5" and 7.25" (or 7.5")
SLUGLINES: Same as Action Element
CHARACTER NAME: Between 4.0" and 6.5" (or 3.5" and 7.25")
DIALOGUE: Between 2.5" and 6.5" (or 6.0")
PARENTHETICAL: Between 3.5" and 6.0"
TRANSITION: Between 5.0" and 7.25"

Format's easy - download CeltX for free.