Is everything pre-destined or not

The Experience/Query posted below was posted by a devotee/Sadhaka.

Pranam Mathangs and Setuu masters

Is everything predestined or not?
Do astrology and planets effect the lives of people?
Bcoz the life we are experiencing right now is due to past karmas

Bcoz if we take great people like Aadi Shankaracharya or Gautama or Ramakrishna paramahamsa
When they were born planets are in extraordinary position
That means planets effect humans lives
They are born to show the right path to the humanity not to lead ordinary human lives

Bcoz to my understanding what I understood was

If jaya vijaya (Gate keepers of vaikunta) were not cursed
Ramayana and mahabharata wouldn't have happened?
Bcoz due to the curse of them they were born as
Rakshasas and lord vishnu has to take birth and to kill them

This is how their destiny was planned
To take birth as enemies of vishnu in 3 lives and to be defeated in the hands of vishnu
after that they will be back again in vaikunta
Here there 3 lives was pre-planned

In ramayana there are many people Said to ravana and vibishna also said that
To return seeta back to Rama
He didn't listen

He didn't listen because due to his samskara?
Or his destiny was planned to defeat under lord vishnu(Lord Rama)?

And again in bhagavatam also

When narada visited sage vyasa ashram, vyasa was unhappy
Narada asked vyasa why he was so sad after writing the mahabharatam also
then vyasa said
" I wrote 4 Vedas and 18 Purana's and mahabharata and iam still not satisfied
My heart is bursting with grief
O sage tell me a way to get peace?
Then sage narada replied
Though you have written all
But you didn't write about Lord vishnu
Who he is?
Where did he come from?
You should write all these
Then you will be happy
Mediatate on lord vishnu and you will know the whole story of bhagavatam
Then you teach the whole bhagavata Purana to your son and he will teach to the king parikshit who is in fear of death (Here narada is saying that king parikshit will listen bhagavat Purana who is in FEAR OF DEATH)

The incident happened when Parikshit went hunting. The King, after pursuing a specific prey in the forest for a long time, had become tired and hungry. This was when he came across the hermitage of rishi Shamika. Unaware that the rishi was under a vow of silence, the King enquired about the prey but the rishi answered not. Enraged by the rishi’s silence, Parikshit placed a dead snake on the rishi’s shoulder with the end of his bow. The rishi still did not protest. Observing this, Parikshit became repentant and walked away.

The rishi’s son Shringi, who himself was highly accomplished in penances, came to know of the insult meted out to his father through Krsha, son of another rishi. An enraged Shringi cursed that the King will meet his death by the live snake Takshaka in seven days

Though parikshit was a noble king but at that time he lost his cool and placed a dead snake on Rishis shoulders

Is it happened? Bcoz as narada said it is destined to happen?
Or is it happened Due to parikshits anger?

Bcoz narada clearly says to vyasa that
You teach this bhagavat Purana to your son and from him the first person who will hear this Purana is king parikshit WHO IS IN FEAR OF DEATH

And It is said that Lord Brahma will write our destinies and he will fix our life span for some X years?

When we go to some Astrologer by looking at horoscope he says that

You will become this you Will become that
You have this mahardasha running that running etc etc

Some will happen some will not happen

And lord Krishna in bhagavatgeeta said that
In chapter 3 sloka 27

प्रकृते: क्रियमाणानि गुणै: कर्माणि सर्वश: |
अहङ्कारविमूढात्मा कर्ताहमिति मन्यते || 27||

All activities are carried out by the three modes of material nature. But in ignorance, the soul, deluded by false identification with the body, thinks itself to be the doer.

In this sloka lord Krishna evidently makes clear that
This world is running by three modes of material nature The fool only thinks that he is the doer of all activities but a learned ones are aware he is not the doer this is all just illusion

And in 2chapter 47 sloka it is said that

कर्मण्येवाधिकारस्ते मा फलेषु कदाचन |
मा कर्मफलहेतुर्भूर्मा ते सङ्गोऽस्त्वकर्मणि || 47 ||

You have a right to perform your prescribed duties, but you are not entitled to the fruits of your actions. Never consider yourself to be the cause of the results of your activities, nor be attached to inaction

Here Krishna says that you have the right to do the duty but giving results is in my hands
He clearly says that Never consider yourself to be the cause of the results of your activities
It's Iam who giving the results

And in bhagavatgeeta in slokas chapter 9 sloka 18 and chapter 10 sloka 8 it is said that

He is saying Iam the whole
Creator and destroyer
Everything happening in this entire universe is happening with my will

गतिर्भर्ता प्रभु: साक्षी निवास: शरणं सुहृत् |
प्रभव: प्रलय: स्थानं निधानं बीजमव्ययम् || 18||
BG 9.18: I am the supreme goal of all living beings, and I am also their sustainer, master, witness, abode, shelter, and friend. I am the origin, end, and resting place of creation; I am the storehouse and eternal seed.

अहं सर्वस्य प्रभवो मत्त: सर्वं प्रवर्तते |
इति मत्वा भजन्ते मां बुधा भावसमन्विता: || 8||
BG10.8 I am the origin of all creation. Everything proceeds from me. The wise who know this perfectly worship me with great faith and devotion.

He says in gita that
I know the past
I know the present
I know the future
But no one knows me

Bcoz if everything is not pre-destined
How would God know the future?

But some say everything is in our hands
We are the creator of our own destinies?

What is true ?

Does really planets and horoscopes effect our lives?
And do our lives are pre-destined?
Or we have the destiny in our hands?

Sorry for the long question

But please reply

Setu Speaks: 

Divine Soul,

Many devotees have asked similar questions and it has been answered multiple times. Please go through the answers other devotees got.

To summarize:

This universe can be seen/experienced/observed from many levels and from infinite perspectives. While pursuing an answer, you must keep the observer in mind because when observer or point of observation changes, everything else changes.

If you see this universe from the perspective of Gods, yes, everything is pre-destined.

But when you come down to the level of humans and do an action, at that point you have the freewill and you have the power to shape your own destiny.

When you are level with the Rishis, they are in middle of ordinary humans and Gods. They can see their own future from perspective of Gods, and can plan their actions at level of humans. When they do something, they get both the feelings. They feel that they are doing action at their own will and at the same time they feel that what they are doing is pre-destined. It happens at the same time. So their knowledge about future does not affect their freewill or vice versa.