Hey there Rippley, Thanks for adding your thoughts.
A lot of what you say here has been mirrored by others, but each individual who comes to the same or similar conclusions independently, matters, so thanks for taking the time to write this up.
You can choose most of your companion subclasses, the exception being characters that pick their subclass at level 1, which at the moment is just Shadowheart, the cleric. Because the others pick their archetype at higher levels, you do indeed get to choose those for them.
If you like pre-building your whole party to be a cohesive combat-effective team that you can tailor the skills of individually, you might take a look at Solasta - in that game, you pre-build your whole party, going through a full character generation for each one. It's not as rich in terms of player interaction with the story, however - you also build your character's basic personalities and social leanings at the start of the game, and then in story elements they will each show you what they would like to say, or how they'd like to handle the situation, and you as a player simply pick which character you want to take the lead and do things their way. It's a different kind of choice-based story telling that involves the whole party a lot more, but it is less immediately immersive, since you end up less anchored into a single character.