If you take the phrase "sole manipulator of the controls" literally, then the only guy who logs actual IR would be autopilot! PF or PNF doesn't matter as long as you're P. What you log is actual time under IMC. I don't know what conditions on mars are, but in central Europe it's about 5-10% of flight time for jet jockeys and up to 25% for turboprop drivers.
You're not either P1/S or PICUS, unless covered by your company trainning programme (and proper designator should be contained there too). Under JAR, the only purpose of PiCUS is to build required 250 hrs of PiC needed for the issue of full ATPL. What some people make out of PiCUS concept is pretty amusing.