Have you involved the LCA team from the WMF in the drafting of this privacy policy? No doubt they would have some helpful comments. I could get in touch with Geoff and Luis about this, if you'd like me to?
" It is based on legal advice and following review of the Wikimedia Foundation's Privacy policy." - not sure if that's WMF LCA, but yes, they would have some useful comments. I'd suggest finishing the basic Privacy Policy off first before asking them to read it though, as there are basic problems such as the link for "please click this link for further details" not existing.
"This policy describes what happens to personal information obtained through the websites hosted at uk.wikimedia.org and wikimedia.org.uk. This policy will be updated periodically." - WMUK wiki is currently on the Foundation's servers so is subject to the Foundation's privacy policy - not this one if I understand correctly?