I usually play as an Agent, but I rarely put points into luck after it prices up to 2 points per rank. You will need strength and endurance, that is for sure. Even as an agent I ended up putting a lot into it just so I could carry everything I needed. Stick with either the ranged or close combat skill and ignore the other completely. If you go as a ranged guardian, you will have higher damage output, but will also want to put a lot of points into dexterity, and will have to make sure you have enough batons/thorns/wands on you at all times. If you don't intend to use magic, don't put any points into it.

For Magic, Blessing magic is very potent in G3, because of spells like steelskin and essence armor, and more importantly, mass energize. It might be prohibitively expensive to rank up to that point, however. Healing counts as shaping, so it should be easier to rank up in it than it was with my agent, and there are a number of crucial spells in it. At any rate, there are a couple of spellbooks over the game that you can read that will boost your healing skill if you have enough ranks in it to understand them, which makes it one of the easiest skills to rank up. There is a challenge area on the first island (testing halls, I believe) where the palyer can get a bracelet that increases their shaping power, and gets stronger with each challenge you complete (five challenges in all). It will greatly boost your shaping skills when equipped, and can enable even lowly agensts (who have the worst shapings skills) to use some of the more powerful creations when equipped. When the creature is doen being made, remove it and equip soemthign mroe appropriate if you wish.

Utilize Greta and Alwan as well as you can. They get mroe powerful as they level up and their attribute increases do not require an essence investment, this can make them invaluable if you don't have the right skills, enough essence, etc to solo play. If they get taken out, they will go back to where you found them (or the inn on the third island, if you have reached that point) but will keep their experience. You may alos consider investing at least enough points into fire shaping to get a fyora. While weak at first, keep in mind that they become more useful as they level. even an unaugmented fyora can be useful (if fragile) late game if it has leveled enough times. try to keep your creations alive if you can. Pick up max training in cure and minor heal from the first village asap, it will help immensely. Vlish, terror clish, drayks, and rotgroths are very useful creations to have, but you might have to use cannsiters to get some of them. pick up a fyora or two asap, and consider adding a vlish (or replacing one or more fyoras with vlish/terror vlish) later on, when you have item(s) that boost your magic shaping skills.

Hope that helped.