Mars is easier to "practice on", and get some toy colonies going, but once scale starts to matter, Venus is better.
At some point, you rather have too much energy and good self-sufficiency at geological scales, than too little energy and bad self-sufficiency.
Of course this stuff has been debated endlessly, but I do not recall reading the "Mars is the stepping stone, Venus is the real deal" needle thread.
If Musk was serious, I think he would admit this, rather than hype-beasting the stepping stone and the real deal.
Floating balloons were considered, but it turns out those have a whole host of practical engineering concerns that rule them out. Plus, getting back into orbit is nearly impossible from said cloudtop balloons. You'd basically need a full sized orbital rocket like the Falcon 9 because the gravity is basically the same and the atmosphere is still a major concern.
He sounded like a loon back then, but not now.