So then everyone goes to hell ? Since everyone goes to the grave. What's the difference between an 'earthly paradise' and 'heaven' ? And what's the requirement to go to one vs. the other ?
Yes, everyone goes to hell where they are awaiting to be resurrected. Even the patriarchs spoke of going into hell/sheol to await the day when they are called out of hell
Genesis 37:34
With that Jacob ripped his mantles apart and put sackcloth upon his hips and carried on mourning over his son for many days. 35 And all his sons and all his daughters kept rising up to comfort him, but he kept refusing to take comfort and saying: “For I shall go down mourning to my son into She′ol!(hell)”
Job prayed to go to sheol so that he could have rest from his troubles:
Job 14:13
O that in She′ol/hell you would conceal me,... That you would set a time limit for me and remember me! 14 If an able-bodied man dies can he live again? All the days of my compulsory service I shall wait, Until my relief comes. 15 You will call, and I myself shall answer you
Rebellious isrealites were said to be swallowed by 'sheol' (hell) as punishment from God:
Numbers 16:30
'...and the ground has to open its mouth and swallow up them and everything that belongs to them and they have to go down alive into She′ol (hell)
This psalm shows that hebrews believed Sheol was the pit for the dead;
Pslams 30:3
O Jehovah, you have brought up my soul from She′ol itself;
You have kept me alive, that I should not go down into the pit
Proverbs 1:12
Let us swallow them down alive just like She′ol, even whole, like those going down into a pit
Ezekiel 31:16
At the sound of its downfall I shall certainly cause nations to rock when I bring it down to She′ol with those going down into the pit, .. 17 With him they themselves also have gone down to She′ol/hell, to those slain by the sword,
So every person who dies, good and bad, go to the same place. And every person who has died will be brought out of the grave too. Jesus said that both the righteous ones and unrighteous ones will be resurrected:
John 5:25
“Most truly I say to YOU, The hour is coming, and it is now, when the dead will hear the voice of the Son of God ... 28 Do not marvel at this, because the hour is coming in which all those in the memorial tombs will hear his voice 29 and come out, those who did good things to a resurrection of life, those who practiced vile things to a resurrection of judgment
Jesus words are in harmony with earlier prophets who foretold the time when all the dead will rise:
Isaiah 26:19
“Your dead ones will live. A corpse of mine—they will rise up. Awake and cry out joyfully, YOU residents in the dust! For your dew is as the dew of mallows, and the earth itself will let even those impotent in death drop [in birth]
What's the difference between an 'earthly paradise' and 'heaven' ? And what's the requirement to go to one vs. the other ?
The difference between an earthly paradise and heaven are this :
Isaiah 66:1  
This is what Jehovah has said: “The heavens are my throne, and the earth is my footstool.
The earthly paradise is mans domain, the heavens are Gods domain. We were not created to live in heaven....our purpose was always to serve God on earth and bring the earth into harmony with Gods purpose for it. To make it a Paradise.
A small few will go to heaven...the requirement is that they are adopted as sons of God by God. They gain this adoption through Jesus Christ.
John 1:12
However, as many as did receive him, to them he gave authority to become God’s children, because they were exercising faith in his name;
Romans 8:23
Not only that, but we ourselves also who have the firstfruits, namely, the spirit, ...we are earnestly waiting for adoption as sons, the release from our bodies by ransom.
2 Corinthians 6:18 “
‘And I shall be a father to YOU, and YOU will be sons and daughters to me,’ says Jehovah the Almighty.
These ones who are invited to become Gods children will die in this life, but will be reborn as powerful spirits....in the same manner that Jesus was reborn. That is called the 'first resurrection'.... the 2nd resurrection is for those asleep in the ground to awake into the earthly paradise. the rest of mankind fall into this category.