I think representative democracy is convenient and useful but my preferred system for MPs would be a hybrid where you can vote on issues or you can choose someone to represent you, chosen by continuous votes of confidence rather than periodic elections. MPs get a number of votes based on how many people they represent, and only MPs with >x% confidence get to vote or propose issues, so it would still encourage building coalitions of interest and a not-ridiculous number of MPs. You would be able to veto your representative on any individual issue which reduces their confidence % at that point, which if it drops below the threshold undoes their vote.

Also non tax payers should not be allowed to vote on any funding or tax proposals.