Does this means that all the choices are made without any chooser ?
To a certain way of thinking, yes.
You did suggest that 'there is no chooser' is only an idea about what is happening . . . and that the only thing you can establish was that a hand and arm moved. So maybe a little more explanation and discovery is needed.
There are two levels.
There is the level of what we THINK is right - And there is the level of what we can FIND is right.
(We can say it like that).
You don't find a chooser in the activity - That's clear to you.
And you said:
Yes, in my visual experience I will see a hand and a arm rise and 'nothing made that happen' or 'something made that happen' is the speculation by thought which arises afterwards.
Yes, so if I talk about thought being 'conventional' . . . we might think / suggest 'I am choosing or I am making that happen' . . . or we might suggest 'I am NOT choosing or I am NOT making that happen'.
There is nothing wrong with either of these statements in a conventional every-day way.
But this guidance is for you to see . . . that's all it is! It's just thoughts and ideas SUGGESTING what is going on. It's the very thoughts themselves that create the illusion. Generally, the illusion is that there is a REAL separate self making it happen, but no such REAL self is found.
In the exercise no chooser was found.
So there is no inherent self choosing. There is no inherent self making it happen.
That's the important realisation.
(Inherent means . . . of itself . . . outside of thoughts . . . We can see that thoughts themselves MAKE the illusion).
Don't worry if this is a little much to take in - It's fine. You've got the essentials of this guidance and you are doing really well!
Does it mean that my life for the most part is predetermined and will be unfolded without any other input ?
Most part? How about all of it?
But you are suggesting 'my life' . . . what exactly is that? What is it that 'has a life' or 'is living a life'?
That might take a big of digesting, but let's move to thoughts now - Imagination can also be treated in the same way.
Think a thought or imagine an object - Anything will do.
Now inquire just as you have been doing - This exercise is the same as all the rest.
1) In the experience of having that thought or experience of imagining the object, can anything other than 'the current thought' or 'the current imagined object' be found?
2) In the experience do you find two things? A thinker / imaginer as one thing, and the thought and imagined object as the other thing? Or is there just 'a thought' or 'an imagined object'.
3) What's making that thought appear? What is choosing what to think?
4) Is there any choice or control over thinking and imagining AT ALL?