Sounds like a good pension plan, its good to have something which could allow you to afford early retirement.
I have a lot of plans in place but nothing on that scale or of that scope, I also dont own a house or other assets as yet which I would see as important. Did you factor expenses into your plan such as renewal of car ownership or maintenance expenses of a property? Those are big things even before you consider all the possible crisis which can occur in that time of a more personal nature, as they say the best laid plans of mice and men, often go awry.
Forward planning, particularly over the longer term, is a great thing, its something I wish I'd possessed a proper insight into a long, long time ago, like when I was in my teens or twenties. Although I think it is something which this generation is more uniquely in possession of than others, what with new emphasis upon time and life logging and what not, there's greater awareness of trade offs in terms of time versus gains than ever, or so it seems to me.
Lots of things which used to constitute obstacles or barriers of ones own making, such as different kinds of self-impeding prejudices, seem to have disappeared and fallen by the wayside, I'm not sure as yet whether that will be a net gain or set back for civilisation as it could simply be that the same thinking of the very rich is now shared by everyone, including the potentially very poor, and any kind of middle ground has just vanished.