I wouldn't worry about it only having one way to wake the screen, it's designed to be pressed thousands of times, so I'm sure it will be fine.
If you're that worried, I'm sure Widget Locker has an option to wake the screen with the volume buttons.
Re the notifications, you could use something like Lite Flow to handle notifications as opposed to the stock apps? You can configure that to have the LED flash for notifications so you know when something is waiting for you. There's also an option to have the screen turn on as well.