Later in the same campaign, our Dragonborn Ranger was in a bare-knuckle boxing match–essentially an un-armed, -armored, combat encounter–with a Pikey-Gnome caravan leader. The Warlord used Commander’s Strike on the Ranger, telling him “hit ‘im where it hurts!” and the Ranger won thanks to the freebie BMA’s the Warlord gave him.

If anyone is wondering what you could do with area-of-effect powers which use weapons, imagine using that power with a shovel to dig ditches. You’d be a living excavator–bonus points if you’re playing a warforged.

Any power which slides a foe, such as Footwork Lure or Duelist’s Flurry, would be perfect for the dance floor, as are Grappling Strike, Slash-and-Pummel (incorporating holding onto your dance partner) and Sly Flourish (for a Sly Finish).

Weapon Master’s Strike, which has a different effect for the weapon you use, is perfect for the Fighter concerned with domestic chores–mopping, dusting, cutting firewood, making dinner, it’s the only At-Will endorsed by pitchman Vince. Retrain in Weapon Master’s Strike and receive a free Slapchop and Shamwow when you level!

Giving them reasonable use of their at will and encounter during a roleplaying situation is key to making 4e something worth playing in my opinion.

I’m not a hater though, I use 4E to run games with people new to roleplaying and D&D because it is admittedly very simple. However, my team of seasoned veterans throw so many questions at me like this ability to talk with spirits that I get overwhelmed. To make everything rely on the few skills dumbs down what could otherwise be a seemingly realistic world with each character possessing unique powers. I find 3.5E systems like Arcana Evolved, Iron Heroes, and other 3rd party products to have more attention paid to roleplaying and utility elements than 4E. But you could also say those games do not have the robust, dynamic combat that 4E brings. It is definitely a give and take.

These kinds of ad hoc rulings are, IMO, more than adequate for stuff like this. If a player has built his entire character around something like speaking with spirits, then yes, maybe that warrants some houseruling, but these are at most isolated cases.

Just for fun, I answered all your questions about the tree. No new rules needed.

What does this tree know?
What does the player want it to know? Roll d20. If you roll low, make up something random. If you roll high, have the spirit answer the PC’s question.

How willing is it to tell secrets to the first humanoid who asks it?
d20. Low = not very likely. Maybe if the player did a quest for it?
High = likely. Some humanoids just fed it earlier, so it’s feeling good.

Should this be a diplomacy check?
Why not? Religion could work too. Shamanism is a kind of religion.

How long can he talk to it?
1d6 minutes.

Do different spirits have different temperaments?
Obviously. Fire spirits are fiery. Air spirits are airy. Earth spirits are…. you get it.

What actually is a spirit at all?
Something a Shaman can speak to that other classes can’t. Maybe they’re just voices in his head.

It seems to me there’s a reason why GURPS and World of Darkness games often involve much more roleplaying: because there are professionals working to create balanced mechanics for non-combat abilities. A +2-5 on a skill check cannot always cut it. Because when there’s no mechanics whatsoever for a Spirit Shaman to use Speak with Spirits to actually Speak with Spirits, the game breaks down. What does this tree know? How willing is it to tell secrets to the first humanoid who asks it? Should this be a diplomacy check? How long can he talk to it? Do different spirits have different temperaments? What actually is a spirit at all?

A game master, in my opinion, should not have to make mechanics on-the-fly anytime a player does something out of combat that doesn’t fit in with the descriptions of a few skills. Characters that seem like they should have unique mechanics that function outside of combat should have those mechanics defined so that they can be effectively integrated by people other than the most experienced DM. Because if people don’t know that they can use “speak with spirits” to actually speak with spirits (since there’s no mechanics for something that obviously needs mechanics, since it falls outside of the realm of normal gameplay) they will not use it.

I apologize if this seems like an attack, it definitely is not. This is just my biggest complaint about 4E and I feel that you are close to addressing this issue.