Most of the people thinks the impermanence is the heart of the Buddhism. But the real heart is
insatiability. People always try to be happy and running after pleasure but the nature of the world is "everything is insatiable". Just because when we can't get satisfied, we just get upset, angry or even this leads to killing people. And also the important part is when we get satisfied we think it's because of the outside world and we get attached to that out side world. (eg: when you find your partner you get attached to her thinking you are happy now because of her (outside world). And you feel you are satisfied, as almost everything is as expected - But the truth is, no matter what you think, it happened because that's how it supposed to happen (The nature of the world -
Hethu Pala). To understand this, is up to you. Keeping this aside if I answer your question as below which is general to both impermanence and insatiability,
- Buddhism speaks about impermanence does impermanence only refer to our experience (the 5 skhandas) or is outisde world phenomena included
and considered impermanent.
Whether it's impermanence or insatiability, The answer to this is, it's not only for the 5 skandas, it applies for the outside world as well. But there are only 6 places, where we can connect to the outside world through these 5-skandas, which are; eye, year, nose, tongue, body and mind.
2 question: Is a dependently arising cycle considered happening in a split second or how fast is it considered happening and what is its relationship and connection with time ??
In this cycle, the 10th Nidana called Bhava has two types, One is which causes to another birth and the other one which causes to
Karma (The reference can be found in
Wibhanga-1 -> Paticca-samuppada-vibhangaya).
So the Karma cycle is happening in a fraction of a second. More details has to be taken from
Abhidaharma section. It explains about time which takes to create one thought in the mind (
Chittakshana, Chitta witi). So in simple Karma-dependently-arising-cycle runs every time we see things, we smell things, we tastes things and so on. The cycle regarding the birth, will happened on the moment of death.
About the time, generally buddha has mentioned to maintain the past, present and future as it's needed to explain things. But mainly the time dimension is something human has built just to explain things. When there are
hethu (reasons / causes) it will generate a
pala (result) as a result.