If a university pays you to do the same things as you would do on your free time, and what you would do on your free time could be considered original philosoph

If a university pays you to do the same things as you would do on your free time, and what you would do on your free time could be considered original philosophy, then yes, it would be the job of "philosopher". There's also philosophers like Stefan Molyneux who make their money from books/donations/speaking engagements.