Having a ranged option on all your characters definitely helps, but melee is still important, because in many fights you get stormed and need someone to hold the line. Luckily, it's easy to build characters that are great both at range and in melee (Shock Wizards, War Clerics, any Rogue), and once you unlock Haste even your melee-only Paladin will never waste a single turn. You also get tons of wands of Magic Missile, so you can rely on that in the rare circumstance that every enemy is taking a walk on the walls.
Click on the "attack" UI element, then click on the enemy.
To craft stuff you need the relevant proficiency and tools (the only one you have to buy after character creation is the rosary, I think), then you need to find (and read) recipes (they have books for icons). As soon as you read your first recipe, it becomes clear how to craft an item.