(1)-(3) just amount to the Corporation of London (the City council) having a different system of voting to other city councils (which are based on personal residency). As the City's resident population is about 7,000 but 300,000 work there, and it's the most important area in the country financially, the system of giving companies a vote makes some sense. Would it really be democratic for a handful of low income voters (several population areas in the City are social housing for those on benefits) to make the rules for the economic heart of the UK?
(4) So what? Parliament has numerous special advisers (Spads) paid from public funds who carry out party political activities. Far more disgraceful IMO.
(5) Of course the City has political input into to the tax process but they still pay the same taxes as everyone else.