Computer Software Question

1

Is it possible to modify a commonly available “free” computer program such that it works nearly flawlessly but whose UI is made so complex that a staffing business could be built around providing temps to operate the software for the end user?
Also, what is a Value Added Tax, and would such a tax apply to the modified “free” software if a customer uses the staffing service?
Asking for a friend.
/image gnu free software question
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