- What ads? If you mean the pop-ups, this is an ongoing issue. They should be about vps updates.
- What nags? avast has every reason to expect a profit. After all the employees want to get paid for their efforts.
- Crashing web browsers? Just disable the “avast online security” plug-in.
- Grimefighter? Uninstall it. Control Panel>Uninstall a Program>double click “avast”>click “change”>untick the box>reboot.
The one thing that really stands out is that you never complained about the protection.
With all due respect personally I feel you are being rather petty.