
Nice job.
It looks like when you slowed clips down Premiere is trying to deinterlace a progressive clip. To prevent this, right clip on the clip you slowed down, click video options, click Field Options, and uncheck the box that says Deinterlace when speed is below 100% and hit ok. That clip should be fine when rendered now. Repeat for each clip you slow down.
If you have a lot of clips you did this to you can also select them all and go to the clips menu and do the same thing to all of the selected clips at the same time.