You’re using C# or Boo, right? You have to assign the whole vector/quaternion at once with these languages - you can’t assign the individual components. This is because the values aren’t variables as such, but properties.
To set the Euler angles of a rotation, you can use Quaternion.Euler. For the angular velocity vector, you just need to assign the whole vector at once.
Nah, it’s worth knowing both. JS is indeed usually more convenient and I use it 99% of the time, but it’s useful to understand what’s actually happening.
Don’t regret learning C#… it’s a lovely language. Not only that, it’s used extensively in industry, so any experience you gain within the world of Unity, will stand you in good stead.