If you want to see the video and set IVS rules, etc., then yes you need to download that plug-in. It is downloaded off the camera, not the internet. Your antivirus may or may not allow it, so you may have to overrule it.More questions:
1. The initial screen has a message: "Please click here to download and install the plug-in". Given that it is an exe., is this a safe thing to do?
2. This camera doesn't have a storage card. Is there a way to confirm that it is working, i.e. by streaming live images to the browser?
When you download the plug-in, you will then see the live images.
If your camera has an SD card slot, we recommend putting one in. It serves as a backup and can be used for troubleshooting motion issues.