TDM re your question in 29: All UK airspace from FL195 to FL245 becomes class C wef 15 Mar; that includes airspace presently classed A, D, F & G. it would seem logical to change the Heathrow & City Zones at the same time; nah maybe it's too logical.
NB There'll be TRA's in it for the military to use, TRA now being 'Temporary Reserved Area' not 'Temporary Restricted Airspace'.