3)Of course it will make no sense for people, they are trained in blind faith in blockchain.
No, it makes no sense because either you didn't explain it well, either is not applicable.
You have to understand that others don't have your background and don't think exactly like you.
Now, you propose instead one dimension - time, multiple dimensions. The second dimension is location. If I understood the things right, you want to improve the blocks in the blockchain.
Now, since a block is mined, since the miners are spread out around the world, since the block can contain transactions from all over the world, I have some problems for you:
1. What would be the relevance of location? I mean, what makes a block mined in Sichuan better or worse than one mined in LA? Is there any difference?
2. Let's say 2 blocks are mined in the same time in different locations. 1D chain will have to decide which
one remains as the good block (temporary fork). In your model both blocks are good. But wait, they contain different transactions - some are in both blocks, some are completely different - correct blocks are needed to see where the money comes from when you spend. How can a MD chain handle this without messing it up because of duplication?