I don't think that there is an issue in single wallet address. It just helps you to prevent trackers from tracking your financial information and activities. However, if you are worried about using single paper wallet address then you can save it to your Blockchain.info account as a watch only address and create another web wallet with the dynamic addresses to receive funds and then transfer to your paper wallet either directly or through a mixer to avoid others to track your information.
Don't see the why do I need to add the paper wallet's address as a watch-only address? As I understood, your suggestion is to first receive money with the online wallet, and then send them to the paper wallet myself. Such that only I operate with the paper wallet's public address directly? But this would double the transaction fees, as I know.