your position is bewilderingly confused, why not limit to 1? you seem to be advocating some disparity of wealth, but then saying there shouldnt be any. if the buy-to-let is such a problem, who would provide rental accomodation, is it best provided by business, by non-profits or by the state...
typical politicaly biased arguements, completely detracting from the root cause - not enough housing to meet demand for a couple of decades. you can throw money at it, let everyone have a £1000 allowance for housing benefit if you want, it wont solve much if there isnt the housing stock...