No. It's not required.
Your Netvue cameras provide their standard features (instant alerts, live view, two-way audio, playback, and so on) without any subscription. Netvue Protect Plans simply offer additional features for those who have higher security demands.

For Android: Click Netvue App > "Protect Plans" section > select service type > Subscribe now > select plans > follow the in-app instructions to complete the subscription process.

For iOS: Enter Netvue Web Client (my.netvue.com) > log in with Netvue Account > click "Protect Plans" section > select service type > Subscribe now > select plans > follow the web instructions to complete the subscription process.

No, you don't have to.
The newly upgraded Netvue Protect Plan comes with bundle price, with just one subscription, 1/2/5/10 devices under one account can be covered depending on your own security needs.

Netvue only accepts digital credit card payment, any payments in the form of cash, check, or money order are not acceptable.

The recording will start automatically right after the subscription. Please note that, videos before the subscription are not recorded and saved to the Cloud.

Access my.netvue.com to manage subscriptions. Click the "Protect Plans" section > Subscriptions > select the subscription you want to cancel/upgrade > Subscription Details > Upgrade Plan/ Unsubscribe.

Access my.netvue.com to change credit card.
Click the "Protect Plans" section > Subscriptions > select the plan > Change Payment Method, then you could add a new credit card for payment.

Please notice, canceled plans do not support payment credit card changing.

Yes, you can. Access my.netvue.com to switch activated device.
Click the "Protect Plans" section > Subscriptions > select the plan > Activated Devices, then you could switch the activated devices.