Yes, you can add as many cocoapods to your app as required, it makes no difference regarding the count of packages.
Many of the most popular apps have a dozen or more packages. However, whether or not you should be using that many packages is an entirely different question.
Also, your point about the MIT license is a good one. You should also be ...
The best course of action is to contact Apple directly and let them know the details of your situation. They should be able to transfer the account holder role, if they want. They would probably require a signed document from your CEO or similar.
For best quality, you will want to use a 1024x1024 original image. Apple usually downscales those for display on its various App stores (unless your app is featured)
In practice, I've (re)submitted to the App Store old 512x512 icon images and even older 114x114 icons that I just upscaled to the required 1024x1024 size using Preview, and Apple has approved ...
If you have homebrew installed you can type in the terminal:
brew install python3
Otherwise you can just download it again from the website and install it.
If you don't know which version of python you have installed type python --version or python3 --version. Similar questions have been answered on SO and other websites.