There is a dimmer switch HS210 coming soon or is already available in some regions. So I don't think there is plan to add dimming to HS200.

They are adding the feature to set away from sunset to sunrise. If it's not working at all, check the device time.

it will go to preset status. Bulb will be turned on. https://www.tp-link.com/en/faq-1575.html

When you ask Alexa to discover devices, what does Alexa respond? Make sure remote control is enabled on the kasa app. Disable and enable kasa skill on Alexa app. And manually click discover devices...

Maximum is 32 events for smart plug. if you can only add 16, maybe need to update firmware?

The plug may be broken if it didn't respond to reset. Did you experience power outage during update? If not, you may report to tplink