My 7th suggestion. Payments by shares.

There is in Ethereum such a thing as uncle blocks (uncle is the brother of the paternal block), these are orphans that are monetized and added to the blockchain and increase its difficulty and safety, due to the computations embedded in them. Uncle included in the unit, receive a 7/8 static block award.
I propose to extend this mechanism not only to orphans (ideal alternative block solutions) but also to shares (non-ideal alternative block solutions) and to pay them a reward proportionally to the degree of ideality of the shares (like in proportional pool system), from 7/8 for ideal orphan and down to the ultimate lower ideality of accepting the share, ULIOATS is fixed and corresponds to the daily work of the statistical middle-user cpu-processor for example core-i5 2400.

This system will provide a guaranteed periodic award for any even for the weakest processors. Due to this, weakest processors will not escape from solo-mining even in case of strong increasing difficulty of the network and increasing of time between their blocks to unacceptable values, measured in years.

The problem of a heavy blockchain, I propose to solve by cutting off the tail of blockchain. Let's assume so: every 50 thousand blocks (with block time of 1 minute - this is about a month) creates a checkpoint block containing a complete list of all non-zero wallets and their balances. And every 300 thousand blocks, the most ancient tail under the most ancient “50 thousand checkpoint block” is cutting off.