I have a feeling Larian doesn't want to overcomplicate stuff.
Bardic Inspiration will be like a AoE Guidance spell that affects all rolls. The time limit may be shorter though, like one minute.
Paladin smites, my guess will be like spells. It will be a melee spell attack, they already do it with Shocking Grasp. I think they will figure out how to not use a spell slot if the attack misses.
Plenty of space on that toolbar for all those buttons...
