I agree that type 1) is the main problem, as I mentioned here : Counter-proposal to oil/karma: per-account gas limits
But I don’t see how the oil/karma proposal would be immune from 1) the problem is that current CALL opcode only enforce a max gas. They protect the parent not the child.
EIP-1930 is a very simple solution to that problem and using it for metatx does not make them opcode pricing dependent as the gas is specified by the signed message.