I agree that flying should be available only at max level for your main character but I couldn't disagree more about having to pay 10k each so that my alts could fly too. Where is the logic in that? I could just level them up to normal and pay the minimal cost my main did. A cost that would be covered just from the gold made questing and selling the green drops and whatnot that I'd likely collect as I went. 10k... Jesus! You're basically punishing people who want to fly but don't have a lot of gold. I don't give a shit how easy you think it is to make gold, some people literally play the game for some fun and only carry about 2k around with them.
Step 1 - First toon - Max level then learn flying.
Step 2 - First alt - Sent a tome from first toon that cost, let's say, 1k.
Step 3 - Second alt - Repeat Step 2.
And I really don't understand how flying breaks immersion. I'm flying on a fucking dragon! How is that not immersive?!
Sure, it's fun levelling through the zones on foot the first time. But then I've done all my exploring on the ground. I want to see stuff from up high, reach places I couldn't reach before. Keeping yourself on the ground only is just shooting yourself in the foot when it comes to experiencing the world and what it can offer.