Eventually you will tune it to D for 99% of your songs and wonder what all the fuss was about.

The many “three chords are all you need!” books and websites dumb down a beautiful instrument. In fairness, it’s more to do with knowing where to begin a strum or picking phrase, as some of the diagrams acknowledge that beginners may think you have six strings therefore every string must be plucked.

The E as a bass pedal doesn’t really work for many “shapes” and if it wasn’t for the blues / rock playing in E, I’m sure it would be D as a standard.

Incidentally, I have always made use of my thumb. For simple first position chords, try it. If I am playing a D, I usually “thumb” F# etc. F for F if barre chords aren’t your thing. You mention Am. Pinky finger on the G.

A guitar is such a chromatic instrument in normal tuning, it’s a shame to be rigid. Experiment. If it sounds good, use it. A nerd like me may point out that’s be use it’s augmented, suspended or some other reason why it sounds nice but don’t get hung up.