x86-64 to ARM transition

Just received my MacBook Pro with the M1 chip, started loading all my apps and as expected some programs aren’t native ARM yet.

1 - Is there an easy way to tell if an app I have open is ARM/x86-64

2 - Will I get a notification or something to upgrade to the ARM binary once the developer of the app creates it or do I need to constantly watch for when the app supports it

3 - Will a native ARM program run better than the Rosetta2 emulation. I.e. if I am running a app now using Rosetta2, should I expect it to perform better once the native ARM version is released?

thanks!