Proposal for the patch 3 spellcasting system. Sorry if this has already been brought up, couldn't find it via searching.
If you select a spell but don't choose the level in the widget it should default to level 1 when you choose a target. Or, the base spell on the hotbar should be level 1 and the widget menu should have leveled spells only.
There's been several instances when I went to cast a spell in combat but forgot to choose a level, and so when I went to click on my target I walked up to them or melee'd them instead of casting a spell. Likewise, when I want to cast a spell outside of combat if I forget to choose a level I would, again, either walk up to my target or I would enter dialogue with them when I didn't want to.