Well, that wouldn't be true; because if they can't, then you also can't add children to the OLD pages using this children. Maybe something along the lines 'May users add children to pages using this template?'
If you want to store what would be monetary values then I'd suggest avoiding floats or doubles like the plague. Go with fixed-point values which are usually strings which you manipulate with PHP's bc maths functions. MySQL also supports fixed point numbers using the DECIMAL() type.
I once heard that you should use integers for these kind of data, as in instead of $3.256 you'd have 3256 fractions of a cent (and do int calculations with that)
1.) I don't think there currently is any nation-specific PW site, maybe short of finland (and that's only because Antti (@apeisa) is a beast)
2.) Whether anybody is working on it, I'll leave that up to german boys
+ RANT: What the hell is that argument that "our clients heard about these before". Well, they are the agency, they should make the freakin' technical decisions! I will never understand this 'client asks for it, we bend forwards and backwards to do it' mentality… Especially when it comes to technical decisions.