While not 100% related to the above, I really feel like they should move being able to crit with spells to be a feature of Arcane Trickster. It kind'a fits thematically and it feels like a bit too strong for a lv1 feature (considering it does scale for some reason with stuff like Potent Robe and Agonizing Blast).
I've honestly thought of so many, many fixes for the class that I'm surprised it's so difficult for them to just bin mage hand and do something different (you know, kind of exactly how they did with the GOO Warlock?)
What about a version of Cutting Words? They have an ability where the Bard saying some nasty words to someone reduces their saving throws...
... so why not give the AT a version of that which works like Magical Ambush? If you're hidden the saving throws against your spells are reduced by D6 (at level 3) and this increases to D8 at level 6 and D10 at level 10? Kind of like a magical sneak attack without the cop-out version of just letting spells proc sneak attack dice (why do that when you can just fire a bow and accomplish the same thing?)
Simple.
Honestly, I just don't think they like the class...