I would like there to be an option for RGB and manual shaking. There already is but it can only move from top to bottom. Please do this shotcut! ps, also make an effect for mirror!
Shake and Mirror already exist. See https://shotcut.org/blog/new-release-180913/
If you want more shakes, use the preset provided in the Size and Position filter and learn from it how to add more keyframes to the desired length.
If you want Mirror to be somehow different that what is available today, then specify what you want different. Reflection instead of flipping?
“RGB” is too generic. Provide a link to a web page or YouTube video for an example.