I just wonder if "Santa's Crew" is genuine charity. I say this because I have experience of an organisation which applied for charitable status. Knowing the hoops that the Charities Commission made us jump through to obtain said status. Things like having to amend/approve our constituion, our in-house rules etc. The difficulties placed in our path because we were a "trading organisation", (We leased some land and sublet it to members). In the end we decided that it was just too much trouble.
I must say that I ambivalent about Santa's Crew's apparent objectives and have no reason to suspect anything untoward in either their collection or distribution methods. Indeed their stated aims could, perhaps should be lauded. It is just a pity that the children have parents that put them it their difficult position in the first place.
There is nothing inherently wrong about having an unofficial "whip round" but it can put the "whippers" in an awkward position whether or not they have broken any laws or conventions. It is all very sad.