Issue 1 has been solved with me replacing the file /system/usr/keychars/mimmi_keypad.kcm.bin with the one from a Norwegian Xperia Mini Pro. This file is the one that maps the keys of the hard keyboard and is the file used by third party text input applications
Issue 2 is basically a non issue since, as previously mentioned, Smart Keyboard has a sort of different icon over the flashing cursor when using this blue function key. So its possible to distinguish where you are in the function realm.
Issue 3 is the one to fix. If this is possible Smart Keyboard would be the only 3rd party text input method to have this working for the Xperia Mini Pro's out there

Maybe it helps that in the file /system/usr/keyboard-config/layouts/qwerty-no-dk.xml (and all other layout files in that directory) Sym/áü button is id'ed as:
<key id="216"
meta="META_SYM"/>
Thanks for your continued help in this matter, hopefully it wont be to long before this can be fixed
