- miners should follow the same rules, but in addition they need to hold transactions at least for 15-20 seconds before including them into the block
It is impossible to know with any level of certainty how long a miner (or pool) has had a transaction in their mempool. Therefore, it is impossible to enforce a rule that requires them to have a transaction in their mempool for a specified amount of time.
- full nodes should reject blocks that consists more than 5% of transactions considered as non-standard (using non-standard scripts | being in the mempool less than 15 seconds | with a fee below 20 satoshies/byte)
If my node receives new block "A" which builds on the current best chain but includes more than 5% of transactions that have been in my mempool less than 15 seconds, and then half a second later receives block "B" which builds on block "A" which follows your rules, what should it do?
- Accept the invalid block "A" so that it can accept valid block "B"?
- Reject invalid block "A", and therefore need to reject valid block "B"?
The main idea is that transaction must get into the most nodes mempools and stay there for some time before it can be included into the block.
Have you figured out a reliable way to know what
most nodes have in their mempool? Right now, a node only knows what it has in its own mempool, and it has no way of knowing if its missing anything or if any other node has any of those same transactions in their mempool.