Usually, when reading posts like that from the OP my reaction is 'don't you read for comprehension?', but in this instance it's clear he has and that he is intolerant of bugs. Usually that's no bad thing, but when you're testing pre-release software, bugs are to be expected and I think many of his issues are down to one particular bug: that the software presents itself for use way too early.
When updating the OS it really is necessary to leave the device alone for some time before touching it. I found this out when, after a particularly hard day at work, I fell asleep during the update process and awoke about three hours later to an updated 920 which has worked quite smoothly ever since and battery life has been reasonable. Neither is as good as WP8.1 mind, but they are usable.
My advice to the OP is to roll back his 920 to 8.1 and install w10 on a secondary device. He can then use the performance of this device to gauge when to upgrade his 920. Remember that Daniel Rubino is running W10 on a Lumia 1520, a device with enough grunt to cover a lot of sins.
Personally, I don't think it's necessary or useful to hard reset every time, because it gives Microsoft a false impression of how well thinks are going. Non-technical users are going to expect to restore their devices from back up after upgrading, so its best not to obviate this issue.