Try it like that, you need 1 boolean variable, can be a player instance var. call it canCreatePlatform for example.
Player > On Jump> Set canCreatePlatform to true.
Player > On Jump--------------------------- canCreatePlatform = 1---------> Set canCreatePlatform to 0
Space pressed ------------------/ Create platform under hero's feet.
Player > On landed > Set canCreatePlatform to 0
Platform > On created > Wait 2 seconds.
Destroy
As for the scroll, I don't know what is happening. Are you using System> set scroll to object (Hero)??