Best single piece of advice for someone trying to play as Pontos: Don't accept the Ptolemaioi offer of a ceasefire. It's tempting, but you are at war with them and an ally of the Seleucids. It will cause the Seleucids (who are at war with them) to get angry and you can count on them attacking you within a couple of years after that. Use that time to build up your cities instead of going to war and losing pretty quickly. Anyway you wouldn't get any trade with them for a while (Ptolemies) since you aren't close enough.