"Hard to have a waist when you're petite...those internal organs need to fit in somewhere!" --- Mochi, thank you, I'm still giggling and nodding to that! (I'm all of 4'10'')
Una, I LOVE this untucked on you --- it looks even more hourglass-y like that. Not sure why, but maybe because the colour transition at hip level makes a wider line that balances the shoulder line? Of course, tucked certainly looks a lot more leggy. SO I guess the two silhouettes address your two concerns in different proportions --- untucked counters IT better, while tucked balances petite more!
That said, I too have trouble with feeling comfortable and neat when tucked, especially if it's knits, which seem to like to bunch and twist and bulge in all sorts of odd ways. By no means am I a neat freak nor polished --- I used to wear cotton tunics and shirts un-ironed as a teen, much to my mother's great amusement and despair. Yet I feel like untucked and unbelted invariably ends up looking neater on me, figure flattery aside.
And I also wish to learn what makes a statement T-shirt!
(Quite the info-magnetic thread, Una! Thank you for starting it.)