True.
It's optional so that those who don't wish to bother minmaxing their character can just pick up whatever drops and keep whamming. For those who do want fine control over their character's attributes, crafting allows even finer control than Origins did.
It kills one-man-army builds. It encourages total army builds. Rather than have everything available on one character, you now have to combo between the members of your party to get the optimal results. It's a different kind of versatility, but it's still versatility. And a more challenging variety to boot.
It isn't. If anything it increases the tactical management. Instead of simply plinking at an enemy at range and switching to melee when he closes in and vice versa, you now have to constantly mind the positioning of your characters. Where are the enemies? Where can I move to avoid the one closing in on my archer? Can I move there without coming into range of another melee enemy? Where are my melee characters? How do I get them to hold of the melee enemies? Can I position them in a choke point? Can I do so while avoiding them being surrounded and losing their defence bonus?
Yes, one character can no longer fight of every single opponent in the game. Yes, you now have to use your party more efficiently. Both of these amplify to the tactical depth of the game, rather than subtract from it.
The reduction of options does not heighten versatility. I almost always spam Pause and Tab keys anyway, so tactical mgt is not increased, as it is my chosen play-style.
And party optimization is not enhanced; one is seemingly coerced into taking all Classes, as opposed to the ones desired based on dialogue, romance, or other criteria besides mechanics. While I prefer to take one from each Class as norm does not mean that my three Mage and Rogue party was not viable. But that may not be the case now.