Premiere Elements 10 on what computer operating system?
What video card/graphics card does your computer use? NVIDIA GeForce or other?
If NVIDIA GeForce, you are probably caught up in the following known issue where the answer is driver version roll back to May 2013.
What specific iPhone version are you using to produce your videos?
iPhone video is typically recorded with a variable rather than a constant frame rate. The answer for this has been taking the video into the free HandBrake program to obtain a H.264.mp4 video with constant frame rate. And, then that H.264.mp4 is imported into the Premiere Elements project with Premiere Elements' Get Media/Files and Folders (in the case of 10).
So, you may be dealing with 2 immediate problems, one of which is obvious with the green video.
Please consider and supply more details. Need clarification on the above, please ask.
Use Quicktime Pro or https://handbrake.fr/ open source transcoder/converter to convert to a different codec and try that file
Without having my hands on your cell phone, my only GUESS is that you somehow changed a setting when making the recordings
As I have already suggested, the HandBrake conversion of your file to H.264.mp4 with constant frame rate version should resolve many, if not all, of the issues that you described. Still, that would offer a fix rather than an explanation for why.
Without knowing the specifications of your iPhone, I cannot know for sure, but the difference in video codec between video files seems highly unlikely for the same iphone.
If you want to explore the difference in video properties between the good and the green, then consider looking at the video readouts from the free MediaInfo (Tree View). But, just be careful with the download and install choices for this program since it is known to travel with unwanted baggage.
Perhaps a safer and yet effective route would be to get the Video Name, Codec, Status from the free GSpot codec utility program.