Yes it does
Yes, you can add beast forms to your Wild Shape repertoire of beasts seen by casting conjure animals. The spell explicitly says the conjured creatures literally are beasts, and a creature of the type beast is all Wild Shape needs you to see in order to add its form to your repertoire.
Though someone might by tempted to quibble that they're not real beasts because they're really fey spirits clothed in the shape of beasts, look at it this way: First the Druid conjures a bunch of spirits that take on the form and behaviour of the real beasts they look like. The creatures so conjured proceed to behave and look exactly like the real thing. What better opportunity is there for a shapechanger to learn a new form to wear, than to see a nature spirit do the exact same thing as they're wanting to learn to do?
But it's of limited use
What you might actually run afoul of is limitations on metagaming, or a DM whose setting doesn't include just any creature you can think of (even if it's in the Monster Manual).
- A DM who wants to limit metagaming would be within their rights to ask you to justify your choice. If you try to summon a Giant Owl but your druid has never seen one before, a DM could easily say "How do you know those exist? You've never seen one. How is your druid "choosing" an animal (s)he has never seen or heard of before?"
- A DM who has developed a custom setting isn't straightjacketed by the Monster Manual and doesn't have to include everything in it. Giant Owls might not exist in a DM's campaign.
This also means that this is much less of a loophole than it might seem — after all, how big is the difference between the set of creatures a druid has personally seen and the set of creatures the druid knows about well enough to deliberately try to conjure? I can't imagine it's a very large number.
But in principle, yes, a conjured animal inhabited by a fey spirit is plenty to learn that form from. Just mind that, if you can conjure a particular animal, it's highly likely your druid has already seen it anyway. This makes this method of acquiring new forms both limited in utility and not much of a loophole to worry about, either way.
No.
The Belt of Dwarvenkind grants knowledge of the Dwarvish language, not the physical ability to produce speech. Beast Form very clearly denies the use of the humanoid languages you know:
your ability to speak [...] is limited to the capabilities of your beast form
If it was a Belt of Wookieekind, the situation would be different.
Best Answer
Yes, a druid in Wild Shape is a beast
For the purposes of creature type you are a 'Beast' (or Elemental at L10) while in Wild Shape form and no longer Humanoid. As it has been pointed out to me by a fellow exchange friend, you are still yourself. Still a druid (with your memories and personality in tact). You never stop being who you are, but your form alters in such a all encompassing way that you do, indeed, stop being a humanoid.
So this is, before anything else, saying everything you are is replaced by that of your new form; including creature type. It then gives you exceptions as to what is NOT altered and thus retained from your Druid form, an exception to the Wild Shape rule.
This does have implications such as 'Speak with Animals' making you a legal target as well as (perhaps the most interesting) anything that must target a humanoid (Such as Hold Person and Charm Person) can no longer target you. Since you are now only a Beast.