Hello.
1) Not long ago I bought and downloaded Sonar Professional via the Cakewalk Comand Center. When I bought it and use it for 12 months do I have to buy it for another $199 to keep it on more year and so on?
 
2) How can I delete or remove a plugin from Sonar Professional (for exampe a reverb plugin)?
 
Thanks.

1) no
 
2) work through the tutorials in the documentation to understand this and much more
 
bonus 3) have fun!

2) Right click on the plug in (in the FX bin) and choose "Delete plug in".
 
PWAL is right though, work through some tutorials and read documentation.
You tube free videos is a plus as well.

You paid for it , it is your forever but without upgrades once the year is up. You can jump back in at anytime for what ever the upgrade price is at that point in time. Say you leave it for a year and a half and see a new feature you can't live without,, just go to your store page and it will tell you what it will cost to jump back in again for another year of upgrades,,, and there are always deals. Pay attention as some are short lived.