You just need a decent accountant who understands how to play this game...
Earning $200k, then paying yourself $15k, and then giving yourself 'dividends' of $150k will very likely trigger an audit. Your 'pay' needs to be considered 'reasonable' for the type of work you do.
You might very well do this for a few years, but if you get audited, you'll get fined for this. Make a better estimate - if someone doing similar work in your region might be earning $75k, so pay yourself in that range, then dividend the rest.
"Pay yourself minimum wage, then you can avoid loads of tax!" is a common piece of advice I hear given, and it can be a pretty big red flag to the IRS (got this from my own CPA as well as other CPAs and other financial/tax people over the last ... too many years to count).
The issue is not so much whether you're an 'employee' or not, but in the US, 'wages' are subject to FICA tax (~13% IIRC), 'dividends' aren't. Making $150k, but paying FICA tax on only $15k, and treating the other $135k as 'dividends' is not kosher, as you're avoiding FICA tax on $135k (not really 100% true, because there's an upper cap on FICA-taxable income at the moment).
It's simply not seen as reasonable for someone who's obviously bringing in $150k to claim they only 'earned' $15k, for example. Furthermore, your future Social Security payments are based in part on how much you've paid in FICA taxes over the years, so someone trying to engage in this will find themselves with reduced SS payments down the road, as well as a probable audit and penalties.
Of course, you are right that this is all still a grey area but I'm sure the laws or precedences are clear in some countries.
That's only true up to £32,010 and if you're earning £125k or so and extracting most of that through dividends, the majority of your dividend income should be attracting 22.5% and 27.5% tax after discounting, no?