Hi, I've missed many messages but you can have a BW in a whole party even if as Boeroer said other classes achieve the damage dealer role better (rogue, monk etc.). My consideration is mostly because in a party I like to play with different classes thus 2 paladins is a little boring, but a BW full equipped and well builded can deal good damage.
For the druid and wizard, you can take them late game, in the last levels they are very powerful and a lot of fun!
Druid build is quite "easy", pick Relentless Storm, Heart of the Storm, Wildstrike Shock and its upgrade, Outlander's Frenzy, Apprentice's Sneak Attack, Two Weapon Style and other spells you like.
For mastery a good choose is Nature's Mark, Taste of the Hunt, Returning Storm and Moonwell (or Form of the Delemgan).
Cast Nature's mark, the 4th level bonus spell, Rentless Storm (or Returning storm for easier encounter), spiritishift and start to kill enemies
When spiritshift is over, you can use Gyrd Háewanes Sténes to regain spiritshift or you can cast AoE damage spells and/or utility/healing spells. Equip with Wildstrike Belt please!
After Caed Nua, when you arrive in Defiance Bay, the game is easier also for mid level caster, so don't worry and hang in there!