op: Q1: When did "Heaven" and "Hell" come into existence?
God has no "time line". He is infinite and eternal! These two spiritual realms were created to carry out His perfect JUDGMENTS.
Hebrews 9:27
And inasmuch as it is appointed for men to die (Body/Soul combo) once
and after this comes judgment,(of immortal Spirits)
op: Q2: "Was it God's will for humans to enter heaven (or to stay on a paradise earth?)
False forced choice. What is " paradise earth "?? Eden?
ALL are DRAWN / CALLED by God. He wants ALL to ACCEPT Him and be saved from eternal separation.
John 6:44
No one can come to Me
unless the Father who sent Me DRAWS him;
and I will raise him up on the last day.
Matthew 9:13
But go and learn what this means:
‘I desire compassion, and not sacrifice,’
for I did not come to CALL the righteous, but sinners.”
Mark 2:17
And hearing this, Jesus said to them,
“It is not those who are healthy who need a physician, but those who are sick;
I did not come to CALL the righteous, but sinners.”
Matthew 22:14
For many are CALLED, but few are chosen.”
Some ACCEPT the LIGHT...the Grace...the spirit-led gifts of FAITH / BELIEF...BELIEVERS!
Some don't and reject God ...UNbelievers.
God is in Sovreign control.
If anyone truly and spiritually seeks THE God, God will save Him from eternal death and judgment.
1 Timothy 2:1-6 (NASB)...A Call to Prayer
First of all, then, I urge that entreaties and prayers, petitions and thanksgivings, be made on behalf of ALL men,for kings and all who are in authority, so that we may lead a tranquil and quiet life in all godliness and dignity.This is good and acceptable in the sight of God our Savior,
who desires all men to be saved and to come to the knowledge of the truth.
For there is one God, and one mediator also between God and men, the man Christ Jesus,
who gave Himself as a ransom for ALL, the testimony given at the proper time.
2 Peter 3: 7-9 (NASB)
But by His word the present heavens and earth are being reserved for fire, kept for the day of judgment and destruction of ungodly men.
But do not let this one fact escape your notice, beloved, (believers)
that with the Lord one day is like a thousand years, and a thousand years like one day.
The Lord is not slow about His promise, as some count slowness, but is patient toward YOU,
not wishing for any to perish but for all to come to repentance. (turn to God)
1 Chronicles 28:9
“As for you, my son Solomon,
know the God of your father, and serve Him with a whole heart and a willing mind;
for the Lord searches ALL hearts, and understands EVERY intent of the thoughts.
If you seek Him, He will let you find Him;
but if you forsake Him, He will reject you forever.
Romans 4:2-3...Salvation: Not by "works"...CREDITED righteousness
For if Abraham was justified by works,
he has something to boast about,
but not before God.
For what does the Scripture say?
“Abraham believed God, and
it was credited to him as righteousness.”
God's has made clear His perfect will for mankind in the Bible. A believer must SEEK IT!
OP: Q3: Does the devil "manage" Hell? If so, does that mean God is using the devil to punish sinful people?
A3: No and No.
The devil/satan/dragon/fallen Lucifer/etc has "followers"/demons, but is powerless to change anything in the "lake of fire" nor escape therefrom.
OP: Q4: "If Adam and Eve said "no" to the snake(serpent/devil/dragon/etc) AND never ate the forbidden fruit (Tree of Knowledge of Good and Evil), would there be a heaven for humans to enter?
A4: Yes. "First Disobedience" is not related to the creation of teh heavenly spiritual realm.
Bye the bye, your icon is probably wrong . The Nails were driven through the "manus" which includes the wrist. NO BONES WERE BROKEN!