I currently have a Caliban bard character who I've tried to give the lowest possible OCR to.
He has 16 charisma and max influence for level 2. The OCR numbers are 12 (appearance) + 8 (global OCR). However, his charisma gives a -3 and influence a -1 to global OCR respectively, which brings Barovia's OCR to 16.
For level 2, I took the Sterling Reputation feat which is supposed to lower global OCR by a further two. However, I noticed no difference to OCR after taking this feat and am still hostile in Barovia. I discussed this with DM Erebus and he concluded that it hasn't taken effect, apparently.