Changing email should work regardless of whether the email provider is supported or not since that is one of the main reasons why players change their emails. Your new email has to be gmail or hotmail though.
You could try these out, not all of them apply since we're not GMS but I guess worth trying?
http://forums.maplestory.nexon.net/discussion/21466/possible-solutions-maplestory-not-launching
This isn't a permanent fix but in the meantime, you can get out of the gachapon menu when you get stuck by going into Cash Shop.
With the extracting problem, is your fatigue full? Or is the issue coming up even when your fatigue bar isn't full?
This is why most guides recommend you to keep extra denaros before you use them because you require denaros in order the start the run. I believe the only thing you can do is start commerci on a different character.
But yes, you can get 1 denaro from the 5 denaro run, the issue is getting more...
https://docs.google.com/document/d/1okuUfdkiYS2dVhz5S-YT3bzJZnaT6-JqMzrWwNZNeVo/edit?usp=drivesdk (Taken from BiS post mentioned above)
Full comparisons made here. And yep, like mentioned above, even getting to 20* takes a long time so technically 15* tyrants are better at the moment.