Definitely had that "Attack roll vs Saving throw" thing come up many times in 5e, especially with a couple of new players. Having a cleric with Sacred Flame (which is a saving throw) and a wizard with Fire Bolt (which is an attack roll) when they are both basic single-target cantrips. I also never got some of the distinctions 3e made with Scorching Ray being an evocation and Fire Orb being a conjuration despite them both being single target fire spells that require attack rolls. Saving throws in general I think are a giant inconsistency to the "the one doing the action rolls the dice" paradigm and 4e's "the attacker rolls the dice" rectifies that.

I do agree that 4e could have used some more standardized companion characters, especially since the shaman spirit companion works unlike pretty much everything else. I think this is probably partly from the fact that companions weren't a PHB1 option; Arcane Power does introduce a Summoning keyword that gets consistently used for all of the wizard summon spells. I don't think 3e or 5e were really any better in this regard (although PF2e is).

On the Orcus thread, someone had at one point linked to someone who had designed build-a-power variants for (iirc) the wizard and fighter. A thought I had a while ago might be to do something like that for each of the power sources, so the arcane power source would define how to build arcane powers with options available to all arcane characters with then each arcane class then adding a few extra options. This might help with consistency since you would expect your "essentially a fireball" powers to be built in the same way while giving identity to power sources (since arcane powers and martial powers might be built differently), classes (since hypothetical abjurer, battlemage, and beguiler classes would have different additions for what they are good at), and characters (since they could essentially craft and personalize their own powers). It would also help with page count since you could have 2-4 pages per power source +2 pages per class for nearly infinite options instead of roughly ~10 pages per class for a small number of options, many of which are just bigger versions of previous ones (e.g. Fireball to Meteor Swarm or Twin Strike to Two-Fanged Strike or Jaws of the Wolf) which would leave room for either more classes, utility powers, or unusual powers that would be awkward to fit into the build-a-power paradigm.