The reason Minato uses marks for teleporting!

[Nakamazi Itchigo]

It simply is more practical. I view FTG like Instant Transmission from DBZ. Goku has to lock on to an energy source to teleport to it. I believe Minato has to do the same and it's easier for him to lock onto the kunai.

This sounds very correct to me! ^^^

 

[HamzaVeli]

Possible !

 

[FleeOnSight]

This actually makes a lot of sense. Minato is very against hand seals as said by jiraiya sensei.

 

[Yeongwonhi]

Ah! good theory, probably right.