To try to get rid of the many bugs that was supposed to be fixed with 8.0.2, but still very much remained on my phone, this is what I did.
I contacted apple support and was told to do a full update and recovery with iTunes, basically wiping the phone and installing 8.0.2 directly, without any upgrading from earlier versions, that may cause issues and leave trash code/bugs. I did see a couple odd things on my phone that may have been caused when updating from first iOS 8 release to current 8.0.2. One thing was two camera storage folders when looking at the device from my PC, in which were many shortcuts to some "Drive" or something. Could not be accessed, could not be deleted. No matter.
Anyhow, I'm now done restoring my backup and all music/apps, and it seems to have gotten rid of an issue where landscape viewing photos or photo folders froze the screen/touch. This was easiest to test since it appeared every time for me. It may have gotten rid of (some of or all) the other issues too. Non responsive keyboard when writing in landscape, screen flickering black when rotating, or my favorite; recording an audio message when rotating text screen... to mention some. I'm sure there are many more I hadn't seen.
To do this you need iTunes on a computer, and preferably a full updated backup of your phone. Backup passwords and secure stuff by encrypting the backup in iTunes (option on iPhone summary tab). Transfer purchases is a good idea to not have to re-download apps etc. Also manually or with other software sync or backup your photos/videos taken with your device (iTunes does not sync this). I do this by accessing the phone storage directly in Windows 7, it appears as a unit in My Computer. Similar ways in different OS:s. After backup is done do following (will wipe phone of all data, need to have SIM card PIN and everything afterwards):
EXTRA NOTE if you have SLOW-MO VIDEOS: you may need to save your pictures/videos to iCloud for the slow-mo vids to work in slow motion after all this. Just a heads up.
1. Completely shut down phone by holding sleep button until you get option to drag on screen to shut down. Wait 30 seconds just to make sure it's fully off.
2. Hold down home button on iPhone, while plugging the USB cable into your computer (may need to have iTunes running if it does not auto-start correctly). Do not release home button until you get an iTunes logo on the screen.
3. In iTunes you should now see a message about updating and recovering your phone. Follow the instructions. After it's fully complete (phone appears in iTunes again and no action is happening in activity window in top of iTunes) you can eject the phone and take the USB cable out.
4. Set up your phone again as if it was new, enter you SIM card PIN, WiFi-password if needed, iCloud etc. At one point it wants to either be set up as a new phone or restored from a backup. Either iCloud or iTunes. Select iTunes if you have followed this. Plug USB cable back in. Follow instructions in iTunes, select the backup you made earlier. Enter password if encrypted.
5. After restore is done it should sync with iTunes (manually select sync if it doesn't) to restore apps/music/books and everything else checked. Except camera photos, which works differently. This may take some time depending on how much data there is. Expect anything from 10 minutes to over an hour. Progress shows in iTunes at the top. Also, this is a good time to untick some apps in the app tab in iTunes under your phone, that you do not use any more. I'm guessing there may be some old ones. If you happen to want some of them again you can always sync it or re download it later again (and things you buy is linked to your account, you don't have to pay twice).
6. Not sure about the camera pics/vids. Seems the official way to do it is to always use iCloud for photo-storage. I don't do this, so this is what I did. To get the pictures/videos back on the phone make sure you have all the pictured/videos you want to sync back to the phone in one folder on your computer. Everything in this folder will get synced, so if you have other junk there, create a new folder first for the sync and move the photos/videos you want synced there. A parent folder to sync with sub-folders for different albums may work, but I haven't tried it. Then select that folder in iTunes, your phone and the Photos tab. I checked "Include videos" too. Apply at the bottom so it syncs. THIS DOES NOT SEEM TO WORK FOR SLOW-MO VIDEOS however, as they get bumped back to regular speed when synced back. I'm sure they still are 120/240 FPS, only played back wrongly. I would call this a software issue from Apple that needs to be fixed. Maybe it can be fixed with a paid sync app or something, I'm not gonna bother with it now.
7. Hopefully enjoy iOS 8.0.2 without the MANY INCREDIBLY BAD BUGS that was in the initial release.