Technically, that's safe, unless you're vs a grappler. Because strikers have an i5 throw, so it would be at neutral by the time the throw hits...Something like that, idk, I haven't played in a while, but I know it's safe.
Yes, but they are all breakable. The only way to inflict guaranteed damage (ie a TRUE punish) is with command throws. The fastest standing grappler command throws are i6. You must then add one extra frame to account for the first active frame, being necessary for the move to work.
Thus, you need 7 frames to guarantee a punish. All neutral "5T"s are breakable from all characters, and are not considered punish tools.
But I can't hop on right now.