Re: lost phone icon
Hello. Welcome to Android Central.
They usually don't disappear. You can swipe the Phone or Message icon off the bottom dock. Have you searched the App drawer/list for a Phone or Dialler icon. Tap the Apps grid icon to show the list of apps, usually in alphabetical order.
This question arises a lot. I took my phone icon off some time ago to check, and couldn't find it. It eventually was there all along apparently, but I still think it was playing tricks on me.