I see you made the important caveat that your initial critique was not Buddhism per se but a pop version of it.
Some reflections:
One of the points you made is actually exactly the same critique many if not most Buddhists make against Shankara’s “Advaita (nondualist) Vedanta, that what is impermanent is unreal. Buddhism on the other hand states almost across the board (as does the entire Tantric tradition of India and the Taoist tradition of China, which has a strong influence on Japanese Buddhism and Southeast Asian Buddhism in general) that int eh experiential world there is nothing that is unchanging, and that seen clearly, it all is real, as the “Dharmakaya.” Whitehead made this insight the foundation of his process philosophy, and many Christian process philosophers have rethought “God” as incorporating both a timeless, spaceless reality AND a dynamic (similar to the Tantric “Shakti”) evolutionary reality, .
Regarding the fundamental importance of thoughts, the Dhammapada, one of the earliest Buddhist texts, states
We are what we think.
All that we are arises with our thoughts.
With our thoughts we make the world.
Speak or act with an impure mind
And trouble will follow you
As the wheel follows the ox that draws the cart.
We are what we think.
All that we are arises with our thoughts.
With our thoughts we make the world.
Speak or act with a pure mind
And happiness will follow you
As your shadow, unshakable.
"Look how he abused me and hurt me,
How he threw me down and robbed me.”
Live with such thoughts and you live in hate.
“Look how he abused me and hurt me,
How he threw me down and robbed me.”
Abandon such thoughts, and live in love.
In this world
Hate never yet dispelled hate.
Only love dispels hate.
This is the law,
Ancient and inexhaustible.
The text goes on to say over and over it is important to make effort (ie free will) and to think every day, to be mindful, attending to one’s thoughts, desires and actions, to think through carefully the consequences of one’s actions and thoughts, and to make effort to direct one’s thoughts toward love, compassion and kindness (I should add, in case you're interested in the philosophic foundations of this, it has been argued for thousands of years as to whether this text is presenting a literally "idealist" philosophy of the world, or something more akin to the Greek Stoics with a more agnostic metaphysical view.)
Peter Fenner has made a good case for the integration of this Buddhist insight with Albert Ellis’ Rational Emotive Therapy.
In fact, this is largely what was done in the 1990s with the integration of mindfulness and CBT, which has been generally shown to be more effective for a wider range of mental health concerns than CBT alone.
Regarding the question of free will, I’m wondering if you’re able to do any of the following: (there are thousands of scientific experiments showing all the following can be done, even if it is quite rare)
1. Choose exactly what you’re going to eat, all day, every day, and eat exactly what you choose – the type of food, the amount, and the timing
2. Choose exactly the exercise routine you wish to undertake, do it exactly as you’ve freely chosen, and follow through for months or years at a time.
3. As you lie down to go to sleep, use your will to control your thoughts to the point that within a minute or so you stop all discursive thought.
4. As you continue into deeper stages of sleep, with your mind fully aware as your thoughs dissolve altogether, remain aware as you enter the dream state, maintaining full ability to choose what to dream about and control all parts of the dream, and then intentionally dissolve the dreamscape as your brain waves slow further to delta waves, you enter deep “stage 3” sleep while maintaining full awareness.
5. Visualize an object, such as a tree, to the point that it is as vivid when you close your eyes as when they are open.
6. Observe a mood of intense anger and within seconds, detach from it so completely that it utterly dissolves (or any craving or negative emotion – have you done this with any of them using your free will?)
On the other hand, can you focus on the sensation of breathing for more than 5 seconds without being carried away by your thoughts?
(By the way in case you read more into these last questions than I intended, I'm not presenting them as "proof' or even evidence FOR or AGAINST free will, simply inviting you to try these experiments in the hopes you might consider the possibility that free will is not quite the very simple black and white proposition you offer).
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