I can only speculate based on what I know. 1 & 2 are already answered from scripture
Jesus said that "In my Father’s House there are many mansions. What I understand is that Jesus meant that there are different degrees of sanctity, and people will be awarded accordingly. there is no need for physical habitation because you will exist in a spiritually glorified state
No need to eat, the glorified body will have eternal imortatlity.
You will be able to visit places after the new world is manifested with the speed of thought. For what God creates will never be annihilated, it will exist in a new way.
A sacrament is a visible sign to signify grace, and to give the grace it signifies, you will be in Heaven because of grace and you will eternally live in the state of grace, so no need for the Sacrament as we need them here on earth.
No need for language as we will intuit knowledge from God like the Angels, and we will have the mind of the Lord, we will know as we are known.
No will not be sorrowful for those in Hell, because Heaven is a state of complete happiness. Sorrow would be useless.
Sin will no longer exist, because you will be confirmed eternally in holiness, with no desire to sin, for you will be enjoying the Beatific Vision
Jesus said that “It has not entered the mind of men what God has prepared for those the love Him.” We do know somethings, but they are a drop in the bucket compared to all that will be experience in Heaven. We do learn somethings manifested in Jesus’ glorified body eg. No more death, or physical need, being able to appear in different places, shining in holy glory, and going through physical things .
Life in Heaven as a soul, or later in the New Jerusalem as body and soul reunited, isn’t so much about what can or can’t be done that we might do now; but that many of the things we might do in the fallen world we live in now just won’t be relevant later.
Most of the concepts in your list are applicable to only the physical world. There is no need for food, private property, language, or marriage in Heaven, for it is a spiritual realm, not a physical realm.
While, yes Heaven is a spiritual realm, it will also be of a physical nature.
We will have our glorified bodies that were made to inhabit a spiritual/physical realm.
It would be inaccurate to say that we will have our physical bodies but not inhabit a realm with physical properties.
Obviously we cant comprehend Heaven but we have some basics. We know that it will be a ‘new earth’. So just as our bodies will be glorified, so will all of creation.
Just because we wont have a ‘need’ for something, doesn’t mean it wont exist. As a poster previously stated, we wont need to eat, but we will simply for enjoyment. We don’t suddenly become less human when we enter the glorified state, our humanity comes to its fulfillment, free of our fallen human nature of course.
As others have said, Jesus has already answered #1 and #2. There is no marriage in Heaven.
As the Bible says, No eye has seen nor ear has heard what God has promised for those who love Him. I believe this is referring to Heaven. So, with that in mind, the answer to the rest of the questions are just my opinion as no one really knows.
#3. At the end of time when God destroys the world and those who will enter Heaven will be given a glorified body so I believe Heaven is a real physical place, not just a “state of mind”. Heaven is also very large. If I had to make a comparison between Heaven and the known universe, the universe is just a drop in the bucket as we will have all eternity to explore it.
#4. I think eating in Heaven is possible but not necessary. After all we have five senses (touch, smell, taste, sight and smell). I don’t see why we won’t retain those senses and gain other senses in Heaven.
#5. No. Don’t really know why, just my opinion.
#6. No. Sacraments are for our benefit while living on the earth to help us obtain Heaven. Once in Heaven, we have achieved the ultimate goal and the sacraments are no longer necessary.
#7. Possible. Out personal knowledge will be greatly expanded. What we don’t understand now will become very easy for us in Heaven.
#8. No. Heaven is pure joy and happiness, no sadness or sorrow whatsoever. Those in Hell are there buy their own choice so there is no need to feel sorry for them.
#9. No. Once in Heaven, sin is impossible as we will be in the presence of God.
I presumed that the OP, in his question #5, was talking about the time before the eschaton. After all, it doesn’t make any sense to ask about “leaving heaven and visiting mankind on earth” after the new heavens and new earth come into being.
Therefore, his question seems to make sense, and the answer about “glorified bodies” isn’t correct. Prior to Jesus’ second coming, we won’t have our glorified bodies. Will we be able to visit earth? Good question. We will be only spirit, not body, so it doesn’t seem that we’ll be able to ‘visit’ in any meaningful way.
Something to consider: When we are in Heaven before the Last Judgement, before we are united with our glorified, spiritualized bodies, we will be infused with knowledge directly from God who created all things. In that knowledge we will understand and know all about earth without needing to go there. After all how do we gain knowledge while on earth, through the senses. As disembodied spirits, with infused knowledge we won’t need senses to accomplish the same thing. So there will be no need to go to earth when we can comprehend it form Heaven. It’s like observing it from Heaven. When united with our glorified spiritualized body we will have all the abilities that Christ had when He resurrected, no need for food, being able to go through matter, radiant with glory, and being able to travel with the speed of thought.