Sorry you are having so much difficulty.
1- 2.6.16 is the latest firmware available. It has been out for 4-6 months. It is labeled Beta.
2- the HTML home page was not updated to reflect 2.6.16. Invoke the Java Discovery Tool again (what you used to install 2.6.16) it will show the actual firmware level on the initial screen.
3- what did you specify as the Device Type when you added the ICON Dimmer? I tried two different variants on 2.6.16. Perhaps I did not try the one you chose.
4- I think the web site the EZSrve is using for Zipcode resolution has been shutdown.
5- I run with NTP. Can you expand on this. The Local option is set, the Date and Time is set, the SET TIMEZONE button is clicked, what happens now? The values are not saved, they are saved but the clock does not keep time?
6- The Action with Rec=0, does it display okay and cannot be deleted or does not display? Can you post the Action, I will define it on my system and try to recreate.
7- Was not sure what the symptom is. The Effect takes place (what is the Effect and can you post the Action) and then the device reverts to its old state?