As peter said in another reply, with fly, meteor shower and starburst, you can handle pretty much anything outdoors. Ring of fire can be really helpful in certain situations indoors and once you have town portal and lloyd's beacon, you can just set a beacon wherever you are, portal out to heal and beacon back in - repeatedly. No need to worry about having healing in your party. The biggest issue early on is spell points - you need to get the promotions and getting past that quest will be the biggest challenge. After that it's a pretty straightforward game.