Can I outline with sharpie or a micron ink pen when painting with acrylics?

Sharpie's a permanent marker, right? It's your style, go for it. If you're happy with the look, fine. If you overpaint the lines, the acrylic should still stick to the inked surface just fine. If you decide you don't like the look then you can always redo the lines with paint or India ink, maybe with a calligraphy pen.
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Sure.. i have a lot of artist friends who use ink. Some acrylic painters, some are watercolor artists. The sky is the limit. Best wishes.