For easily launching spells, using skills and equiping weapons we added the 'quick menu' which you can open by clicking on one of the 3 buttons under the stats bars. You can see the available items and activate them by double-clicking / middle mouse button. Some of the spells can also be dropped on objects to use the spell on the object (e.g. healing a player).
By clicking right to the item and typing a key you can assign key shortcuts to skills/spells/weapons for easier activation.