No countdown timer in the stock camera software, at least on AT&T. I got the Camera JB+ app which is basically the stock Jelly Bean camera found on Nexus devices, It is pretty feature rich (to include a countdown timer) with image and video size settings options and many other available settings. It does not have photosphere though. I use this in place of the stock camera on occasion.
https://forums.androidcentral.com/e...com.moblynx.camerajbplus&hl=en&token=NnGZsrkR
When you get a text the screen does not wake completely nor is there a traditional popup when the phone is in sleep mode. There is a notification of the incoming text with a text message symbol on the screen (active notifications). Like has been pointed out, it is a little difficult to explain and its best to check out a youtube video review to see it in action. Much better than a led notification light in my opinion.
Waking the device can be done in a variety of ways. The hardware sleep wake button, by dragging an active notification up to open the notification directly or what I usually do is as soon as I pick up my phone or take it from my pocket or holster it shows the time and a lock icon on the screen. If you drag the lock icon downward it unlocks the phone. I rarely use the hardware button for any reason except to put the phone to sleep if it doesn't timeout first.