2) There are two axes of "simple" for characters, simple to build (which includes learning subsystems, making level-up choices, and preparing things in-game) and simple to play (which includes number of decisions per round, breadth of options, and number of rules subsystems you need to know). 3e has all four possibilities:
- The binder is simple to play but complicated to build; figuring out pact-making, pact augmentations, vestige synergies, and such can be daunting, but once you've bound your vestiges your options are fairly manageable and straightforward.
- The beguiler is simple to build but complicated to play: you make barely any build decisions at all, but handling the minutiae of grappling, debuffs, illusions, nonlethal damage, etc. can be fairly complex.
- The warblade is simple to build and to play: you can pick maneuvers essentially at random and still be pretty effective, and anyone who's played card games can figure out expending and regaining maneuvers.
- The bard is complicated to build and to play: you have lots of ways to build your bard based on what aspect you want to focus on (music, spells, skills), and the bard's jack-of-all-trades nature means you hit lots of rules subsystems during play (conditions, illusions, music uses, spells known, etc.).
You'll notice that all four example classes are tier 3. It's possible to balance simple newbie classes with complicated veteran classes as long as you're willing to accept varying optimization floors and ceilings--it's hard to either screw up or overpower ToB classes, but bards have a reputation of being weak because they require more effort and more splats to make competitive, for instance.
WotC seems to have the mistaken impression that casters = veteran and noncasters = newbie. That was more the case in core 1e, when fighters had no class features and were for players who didn't roll high enough to have a "real" class, but that's not at all the case these days. WotC could easily make simple casters, simple noncasters, complex casters, and complex noncasters to satisfy everyone if they could get over the "fighters get fewer and weaker class features" hang-up.