We also saw 2 big problems. High amount of unconfirmed transactions and exchanges that couldn't handle the trafic.
both of these problems always exist. they have little to do wit the $20k and they are not specific to that high price alone.
In my opinion we never could handle 20k per bitcoin.
only because price went up more than 100% in less than a month and that is a bubble.
1.Can we see a price of 20k per bitcoin today? Without high amount of unconfirmed transactions and exchanges that can't handle the trafic.
if it goes to $20k today then there will be the same surge and both backlog and traffic to exchanges will increase so no we can't handle it. but if the same solid and slow rise continues the backlog and the traffic to exchanges will remain the same manageable lelvel.
2. Lightning, can everone use it, or is it too early yet?
you can use it and thousands of people are already using it. but it is early to seriously use it for important transactions.
3. How much of the network uses segwit? charts?
http://segwit.party/charts/4. How many transactions/second can we see with todays segwit use? And full segwit use?
i think about 10% increase but not sure.