How to change keyboard key locations and functionalities?

Although I am unsure whether this is the best place to post, I do hope somebody here could advice me how to achieve the following. There are several things I would like to have changed in my effective keyboard layout.

1. Several keys are missing on my notebook-keyboard; I would like to locate those on the CapsLock-key:
"CapsLock": CapsLock
"Ctrl"+ "CapsLock": Menu
"Alt"+"CapsLock": Insert
"Ctrl"+"Alt"+"CapsLock": SysReq
"Fn"+ "CapsLock": NumLock
"Fn"+"Ctrl"+ "CapsLock": Pause
"Fn"+ "Alt"+"CapsLock": ScrollLock
"Fn"+"Ctrl"+"Alt"+"CapsLock": Break

2. Furthermore, PrtSc is located at an inconvenient location (right next to AltGr), therefore I would like to move it to the Insert-key (above Backspace).

3. The former PrtSc-key is now available to redefine as a new modulator key, "Mod4", to double the number of characters per key. For instance:
"": (backslash)
"Shift"+ "": | (vertical bar)
"AltGr"+ "": ¬ (negation sign)
"Shift"+"AltGr"+ "": ¦ (broken bar)
"Mod4"+"": – (en-dash)
"Shift"+ "Mod4"+"": — (em-dash)
"AltGr"+"Mod4"+"": † (dagger/obelisk)
"Shift"+"AltGr"+"Mod4"+"": ‡ (double dagger/diesis)

4. Then I would also like to have the possibility to lock these:
"Fn"+"Shift"+"CapsLock": ShiftLock
"Fn"+"Shift"+"AltGr" : AltGrLock
"Fn"+"Shift"+"Mod4" : Mod4Lock

5. Additionaly, I would appreciate it if "Ctrl"+"Left", respectively "Ctrl"+"Right" (which do not seem to do anything) have the same functionality as "Alt"+"Left", respectively "Alt"+"Right", i.e. go backwards one page/file/directory, respectively go forwards one page/file/directory (very useful browser functionality; cf. "Ctrl"+"Left" (go to previous tab), respectively "Ctrl"+"Right" (go to next tab)).

6. Last but not least, I dislike it some diacritics are scattered across the keyboard, and others seem to be missing, therefore I prefer to move the diacritics (dead keys) to "AltGr"+F-keys, e.g.:
"AltGr"+"F1": diaeresis/trema/umlaut (e.g. ü)
"AltGr"+"F2": acute (e.g. ú)
"AltGr"+"F3": grave (e.g. ù)
etc.

Could anyody explain in detail how to do all this?