iphone power user 2 galaxy fan

I've been an iphone power user since iphone 3. so far, loving the note 5. hopefully someone can help with these issues:
1. default apps - is there a way to change the default mail app to either 'nine' or 'outlook'. something that could also work with voice commands.
2. camera - is there a way to have the "PRO" mode as the default when opening camera.
3. phone connected to BT in car, calls go through fine. but when i want to send a text, and click on the microphone on the keyboard, i can't get it to go through the car's BT. (my iphone worked perfectly in this situation)
4. package disabler - is there a way to find out what each package does, to determine if something is safe to disable or not.


Android Expert
You can clear defaults on any app in app manager, so if gmail is default, clear it, next time you want to send email it will prompt you to choose a default.

No way to change the camera start that I know.

I don't have BT in my car, can't help there.

To me package disabler is pretty much common sense, disable what you don't use, if you don't know what it is leave it alone. You can also search for it and see many lists of what others have disabled.