You’re calling the Druid overpowered because you can both cast and attack with the same attribute? I take it you would build your one-stat Fightizard with 20 Wisdom and charge into melee with an amazing 15 AC to use your single Beast attack, doing as much damage as a sword and board 19AC Fighter.

You don’t get both full melee and ranged, you are directly limited by your encounter and daily powers. The more Beast powers you take, the less you’ll be able to cast.

Not to mention the additional actions you need to make so you’re in range/not going to provoke and in the correct form.

Another example: A WIS/CON caster druid that shapeshifted and moved into melee to Pounce to enable CA for the Rogue. Good luck getting out again. You can’t just shapeshift back and shift out of melee; you’re standing just 1 square away from whatever you were hitting, with whatever low INT you have for armor. And ideally, you don’t want to make the Clerics job harder as you said it yourself, you don’t have Healing Word. So you’re stuck for one turn while you try to disengage. If they keep shifting to you, you are basically locked out of your casting until the Rogue manages to kill it. Or you use both your move and standard to run away. Well done, you just did nothing productive.