1) The volume control is a known issue of sorts on the OS. I am not sure why Microsoft did not address this in WP8. It makes no sense to have the music volume control the ringer volume.
2) For the typical user, email settings are fine. I have no issues putting several email accounts on my phone, including a passkey protected government encrypted account.
3)No comment.
4) You are complaining about a feature that very few WPs have, actually only some of the HTC phones have the LED light notification. If you purchase a wireless charging device from Nokia for your 920, they do have LED indicator lights. Solid light for charging, blinking light for completed.
5) As others have said, you can share FB directly through camera roll. Make sure you linked you account via the settings. If you did, there is something else going on. Investigate that.
6) Never had any issue with updates. Or that wait for Wifi message you mention. I cant think of which Lumia 920 update you would have had that needed wifi. All the small Nokia updates so far I have downloaded via LTE.
7) No comment
8) My phone also gets warm when doing basic things, but many of my phones I have had do that. They are not getting hot though. I think it is normal. I have also not seen any issue with battery life in my device. Always lasts through the day or at least near bed time.
9) No app that I know of diagnosis energy consumption.
10) The status bar not being there constantly is a good thing I think. Unlike the iOS where the status bar actually takes up part of the screen, the WP one doesnt and therefore needs to be hidden. It actually looks bad on top of text and other things. Scroll your start screen down a ways then bring up the status bar. Yeah hard to read and ugly. Anyways, you can also get the status bar while in IE (by tapping the three dots button). I am not sure why you cannot just tap the top of screen like normal. Presumedly so you dont try and tap a webpage but then get the status bar, but this theory should be true for every app and experience, so I dont know. There must be a good reason though.
11) Havent had a problem with IE when there is no internet. It gives a similar message to that which a PC would give. Something like website not available or such. Can you really complain about this. If you are going to a site and that pops up. You cant tell me you dont know that your connection is offline??
12) Detects my home network just fine. Usually within 10 seconds of walking in the door of my house. tested this a few weeks ago.
13) You can easily see what connection you have by tapping the status bar. If the wifi symbol is filled it (white color), you are on wifi. If the wifi symbol is greyed out and you have a cellular connection on there, you are on cellular. If the wifi connection is greyed out and you have the no-signal symbol, you are offline. It is a pain to turn cycle connections in the OS, but there is an app (not sure what it is called) that you can pin the option to your start screen to toggle wifi and celluar and airplane mode and such. I am not sure if it is a button or just basically a shortcut to the menu where the options exist.
14) No comment on haptic keyboard.
15) I am guessing you are just not used to the message sending layout yet. The send button is close to the area, but no so much that you should perpetually be sending early texts. Once I got used to its location, i rarely if ever send a message by accident.
16) I dont use bluetooth.
17) No comment on GPS being required for locations that dont use it.
18) No comment. DOnt use Nokia Music.
19) The back button seems very logical to me and I personally dont think you have the issues you are mentioning. The back button will always take you back to the screen you were just at, whether you are within and app or not. I have found a two notable exceptions to this which is maybe what you are talking about, but it is not across the board. If you come into IE from another app and want to go back to the last webpage you were viewing, the back button will do you no good. It will take you out of IE. The fix is to use the "recent" option which you can see all your last pages. Also, in the Facebook touch app, the back button on the phone is useless as it takes you out of the app no matter what. You have to use the built in back button which is quite hard for me to get used to. Otherwise, the back buttons functionality is solid, except for a few developers who fail to use it the same.
20) Multitasking issue. The installation of maps was the only issue I have experienced. I am guessing this is because they are built into the OS. The only gripe I have in relation to multitasking is you cant close apps from the background. Also, background apps just randomly close if you open too many other ones.
21) See #20. I personally never really bother with worrying about which apps are running. My battery seems adequate for me.
22) No folders. But like others have mentioned, just put your frequently used apps on the start screen. Even if it is way at the bottom, it works. less used apps for the apps list.
23) No comment. I dont use linux.
Overall most of your issues seem like you are having a tough time meshing with the WP8 OS as a whole. And seem like subtle nuances that you looked for coming from the N9. I bet if you made a list of things that are better that your N9 did not have, it would be longer. Many of the issues you have just come about from lack of knowledge of the OS. Give it some time. I am sure you will be satisfied.