You can definitely get an IMCR without a night qualification. The UK CAA has not advertised this option at all but pilots who failed the CV tests have managed to get the IMCR with a 'day only' restriction.
Regarding the JAA IR, I have no idea.
Personally, before exploring some esoteric options, I would try to get a CV pass somehow. You have to do this only once in your whole life. After that, you just pull out that letter every time you turn up for some aviation medical and they have to accept it.
It is illegal to base and fly N reg planes in Denmark as a Danish citizen
You could revoke your Danish citizenship.
Revoking a UK citizenship is easy, but they won't do it unless you can show that you have another one to move to. And there is a wide choice of 3rd world passports you can purchase. The trick is to get one which enables you to carry on living at home
If you revoke the Danish one and buy a passport from Bolivia ($20 ??) then you lose the right to remain in the EU (or anywhere else...). You would probably be OK if married to a Danish girl (maybe better if she is pregnant) but the picture is complicated.