It can get difficult re who sits where and their respective duties
No-its fairly simple-just RTFM.
The RFM clearly states the minimum crew required, and which seat to be flown in.
In the case of a Bell 212, it usually says "Minimum crew is one pilot, flying in the right hand seat".
If you want to fly single pilot from the left hand seat, make sure your Ops Manual says so-and you´re legal to fly.
The "habit" of putting two pilots (or even three) into a single pilot helicopter, all logging "multi PIC time" led to the problems we are having nowadays with two "experienced" crew in the cockpit of REAL multi-pilot operations, both unable to work together, as "CRM" is something they only heard about once...