The Alt Tab error is a legacy "fix" that FFXIV got from FFXI.

Tanaka/dev team make that the client crash when alt tabing just because it will be fair and give everyone the same experience of playing, since a lot of people play on the PS2 and there you don't have any kind of Alt Tab...

I guess that since FFXIV was meant to have a PS3 release the dev team do the same shit like on FFXI.

Since both games have the same "fix", the community have both time come with a Windower third party program that make the game run as it should from begging...

Anyway, don't expect any kind of fix until 2.0 and maybe there wont be any fix since on 2.0 there is the PS3 release (That would be dumb to do but well, dk what will Yoshida do).