Hi AKvan,
Interesting observation: “However aniccha, the fact that we cannot maintain anything to our liking, is not a characteristic of the object but a perception we create because of that object. So there has to be someone who sees that object as niccha or aniccha or asubha etc. Without that person seeing it that way there can be no aniccha in that object. So it is we who cultivate that niccha or aniccha perception of an object. Therefore aniccha is not a characteristic (lakkhana) because if it were a characteristic anyone looking at it will see it like that.”
From SN 22.57…
““And how, bhikkhus, is a bhikkhu skilled in seven cases? Here, bhikkhus, a bhikkhu understands form, its origin, its cessation, and the way leading to its cessation; he understands the gratification, the danger, and the escape in the case of form.”
It is evident in this sutta that the danger is Anicca, Dukkha, Anatta:
“The pleasure and joy that arise in dependence on form: this is the gratification in form. That form is impermanent, suffering, and subject to change: this is the danger in form.”
The last part of the sutta says…
“And how, bhikkhus, is a bhikkhu a triple investigator? Here, bhikkhus, a bhikkhu investigates by way of the elements, by way of the sense bases, and by way of dependent origination. It is in such a way that a bhikkhu is a triple investigator.”
Agree with you that Anicca, Dukkha, Anatta is meaningful only when there is an ‘observer’ contemplating the phenomena. As illustrated above, the observer investigates by way of the elements and their derivatives (external phenomena), by way of the sense bases (via 5 khanddhas), and by way of dependent origination (the causal relationship between the first 2 entities).