What do you mean "Somewhat complex; decent complexity for inexperienced users"? Doesn't average user send bitcoins with segwit exactly the same as before?
Complex as in implementation, not the usage. Using Bitcoin will be pretty much the same.
How much is the confirmation speed impaired when the blocks are full?
It is not if you include the right fee.
This. Bitcoin Classic is an obvious solution which solves this issue for the next two year. Large miners support it.
So WTF is the issue then?
1. It is not an 'obvious solution'.
2. It does not solve anything, especially not for 'two years'.
3. They withdrew their support.
4. You wouldn't be asking such questions if you actually spent time reading threads. Two words: Validation time.