If you can, I recommend using the collar to kill one last boss before you start a new run. If you have a spare water or two, maybe collar, end the day, and collar again before using the gem. It'll net you another 2-4 points.
Thunderbolt can be a big help against stuff like the Minotaur, Ogre Commander, and Avian, but the mana consumption is pretty taxing early and I'd recommend scrounging up the points for a starter slime instead.
While technically free to learn, Fire can be great since it allows you to get the star metals in the bandit and refugee camps without needing to get/keep Charlotte out of jail(although leaving her in jail delays Fire II, which is needed in the underwater sections). More importantly: it gives you the option to get those star metals on day 1 and hit the level 5 workshop milestone early.
Water Skin speeds up the engagement ring and stolen food quests for early leveling and makes the bandit leader bounty easier as a possible alternative to the Ogre Commander.
Given the hints to your playstyle in this thread so far, you might enjoy starting with Desmond's proficiency skills if you've learnt any.