What are the properties of your source media that are going to the Expert workspace Timeline?
Is that 1920 x 1080 @ 29.97 progressive or interlaced frames per second?
What are you or the project setting as the project preset for this project? You may have to set the project preset manually if the program is doing an automatic set and it is not correct.
When you drag your video to the Timeline for the first time, what is seen at the top of Timeline directly above the
video on VIdeo Track 1
a. no colored line
b. green line
c. orange line
If you see an orange line, does rendering the Timeline improve the playback situation?
An orange line over the Timeline content when first dragged to the Timeline may imply that the project settings are not correct for your video properties.
Let us start here and then we can decide what next.
Part of the issue is that your processor is way way underpowered for this kind of video editing.
Ideally you want a processor that rates at least a 5500 or more on these benchmark tests.
Your processor rates about 745.
The answers will be in the details.
The links provided in post 2 are impressive but do not necessarily tell us what you can do in your specific computer environment with your specific source media and your Premiere Elements 12 project in a 64 bit system, assumed to be either Window 7, 8, or 8.1. Please confirm what version/editor of Windows is being used here as well as the size and scope of the projects that you intend to create in the future in the computer environment that you outlined.
Granted "..Part of the issue..." is included as a modifier when your computer rank of 745 was pointed to. At this point, I am not ready to pass judge that your "shaky video playback" is related to your ADM E-350 processor.
Once we know more including
a. Do you have the correct project settings
b. The duration of your Timeline content...what parts of it are shaky, all or just some...if some, have you applied any effects to that content...etc.
c. In spite of "shaky video" seen in the Edit Mode monitor, do you see the same "shaky video" in the export of that "shaky video" Timeline content?
Please review and not be discouraged at this rank "745" just yet. It is interesting information to have in projecting the compability of your workbench to create larger projects. But, once the display issue is defined, then you can explore and experiment in searching for the limits of your setup related to the size of the project.
That is my take on the situation in discussion. Do not give up until all the details are sorted out.