1) Polarisation is mainly an issue with ES floor and table lamps. Most of these have a Euro plug, which isn't polarised in any type of socket.
2) There are non-polarised CEE 7/5 sockets, or more precisely, mirrored double sockets with the earth pins in the centre.
3) One could easily design sockets that accept either CEE 7/4, 7/7 and IEC 60906 or 7/6, 7/7 and IEC 60906 plugs for an easy transition
4) The biggest issue trying to replace BS1363 with anything else is the unfortunate fact that BS1363 sockets can be on circuits up to 32 amps and rely on fuses in the plugs for short-circuit protection. On the other hand, Ireland requires any electrical work to be carried out by professionals, with hefty fines of up to 6000 Euros for DIY work, so safely upgrading existing installations doesn't seem impossible. Ring final circuits would have to be split into two radials, radials could be downgraded, provided they aren't too large.
5) Shuttered Schuko sockets are readily available and becoming more and more common. Some EU countries already require them everywhere, others in places like kindergartens.
On a side note regarding circuit overcurrent protection: more careful Germans tend to worry about the capacity of Schuko sockets to carry the rated 16 amps for extended periods of time (some claim manufacturers only rate them for 1 hour at 16 amps and 10 amps continuously but I haven't found any reliable sources for that, many people get seriously confused by the historic 10-/16~ rating) and especially moderate overloads, as a B or C16 MCB can survive 1.45 times its rated current for up to an hour. The French on the other hand happily install identical sockets on C20 MCBs, according to one source even C25.
