Thanks for asking Mike!
Yes, while an advanced player will find a lot to like in the Every Whistle, it is also quite suitable for a beginner. In fact, I was a beginner myself when I designed it, and thus I wanted it to be easy to play. Air requirements are low for the volume. The only way to use less air is to make a smaller wind way, which would make the whistle quiet to the point where it would not be useful in a session.
That said, by closing the "Parks Tone Ring" down, not only do you make the whistle quieter, but you also reduce the air requirements.
My whistles are appropriately loud and shrill at the top of the second octave when the Parks Tone Ring is fully open. Not as loud and shrill as some however. In time, when you learn to finesse the whistle you will come to control and appreciate this character as appropriate to the music and the instrument. But by closing down the "Parks Tone Ring", the upper octave is the first to be tamed, giving you a nice somewhat airy sound without reducing the volume very much.
At the other extreme, if you close the Parks Tone Ring until it is open only a crack you can play at a whisper. I've had one customer who wrote to thank me for the tone ring because it allowed him to practice on a cross-country flight without disturbing the passengers nearby. But my favorite was a fellow who wrote to tell me he could play in bed while his wife was asleep!
So yes, by all means, try one of my Every Whistles. If you find it not to your liking you may return it.
Here is one of my customers, Tiffany, playing "An Feochán" (Gentle Breeze) on an Every D whistle. [Click to play]
You can't rush the training of your muscles. You just have to play, play and play some more, and the skill and ability will accumulate within you. Only play when you enjoy it, and put the whistle down when it is no longer fun. You need to do this to allow your body to assimilate what it has learned during the session. I find several shorter sessions per day are better than one long one.
In the early stages you are teaching your body how to make the sound you want, so the notes of a tune or song are not as important as just making the sounds. Play things you know by heart. Don't struggle with dots on a page and try to learn to map them to finger positions. This will only be a liability in the future, involving way more of your brain than is helpful. Learn the tune so you can hum or whistle it with your lips before you try to play it, then play without looking at the dots, unless you just can't figure out what that one note is - then identify the note and put the paper away again.
A friend at our session recently related a story. He was at a music seminar and one of the students asked another "So can you read music?" The second replied "Oh yes, I went to Juilliard. How about you?" "I can read music some, but not so much that it gets in the way of my playing."
Good luck, and enjoy the journey.