I think restricting flying up until level 70 or even having a longer timespan for TBC content with a possible timely release of content is not only a great idea but also very needed features. Most of the people around this server seem to me alot of the brainwashed mcdonalds generation (I want it fast and I want it easy)... Would be an awesome thing to cleanse and purge them from here once and for all, this would definitly help in doing so.
Restricting flying mounts untill level 70 would be the most stupid custom idea ever. If this get's to be done, they should change the 3.3.5 talents and everything else back to 2.4 content. Honestly, leveling up to 70 at x1 rate just by walking isn't even fun, I suggest for the people who desire this to setup a total new pve realm with the desired extreme hardcore features for only those who want it.
It's not custom with regard to TBC standards. Lol at comparing a relatively simple change like that to altering entire spell designs and talent changes.
And quit crying. 60-70 will be dramatically faster than 1-60 was. There will be lots of 70's within the first 2 days.