Regarding your first question, yes you can download multiple versions of AutoMate to different machines. However, each installation would require a separate license.
If you are running the Desktop version of AutoMate, you can either install full versions of AutoMate on the additional machines or you can install "runtimes" which are versions of Desktop without a GUI. You can find more information on Runtimes here:
If you have Enterprise, you can install additional agents to run jobs, however again, this would require additional licenses.
Regarding your overall issue, your jobs are interactive in nature, and thus unfortunately cannot be ran at the same time with other interactive jobs. We recommend spacing out the jobs, so that they don't "run on top of each other". This would eliminate the need for additional licenses, but obviously, they wouldn't be running at the same time.