Let's go for parts.
You can download the trial version of AIS at the web site of Avast, and then, after installation and reboot, add your license to turn it into a complete (not trial) edition of AIS.
As long as the license is used simultaneously in only 2 systems, you could even use it 1 year with your current system, and then change the whole system for a new one and start with a new stable trial version again. Just adding the license file, you turn it into a complete full AIS, always until the same date (no matter if you use it or not, the expiration date of the license file will be the same).
For the 3500 events issue, it has nothing to do with avast. It is just iYogi's issue. Do you want / need iYogi? Do you have any problems in your system? It's up to you.