I personally think that a fair system should provide an absolutely even start in life to every citizen, then beyond providing free healthcare to all (because most often health problems are not the result of bad choices but bad genetics, bad luck or environmental pollution) leave them alone to make the best of their talents, and no passing of advantage on to following generations.

You don't think that a large part intellectual ability and manual dexterity are a matter of genetics just as much as a large part of physical health is a matter of genetics? Even if a society of 100% super geniuses existed they would still need people to pound nails, pick fruit, haul garbage, make clothing, clean the toilets in public buildings etc. Such a society would welcome with open arms people who were willing to spend 100% of their working hours doing these kind of humble but necessary tasks. Is is really justice that people who work hard and dedicatedly doing society's dirty work should be poorly paid simply because of their genetic endowment? (Am speaking of an ideal level playing field situation. The real situation is even more unfair because circumstances of birth often play an important role in economic success in addition to genetic talent.)

Furthermore capital markets (I distinguish capital markets from markets for goods and services) which give people more money simply because of the fact that they already have money can never represent a level playing field, not to mention the fact that such markets cannot function effectively without composite growth of the over all economy and are therefore inherently destructive in a world running up against resource limits.

My idea of a fair economic system has two components. One component is that the only way to earn money would be by doing constructive work. No one should be able to earn money simply by virtue of already having money. Of course one can conceive that people with good business acumen in a systems sense, who are capable of evaluating the potential for success of proposals for new enterprises or for expansions of existing enterprises would be providing a valuable service to society. However, such people should be rewarded for their hard work and intelligence and not for the volume of money that flows through their hands. Once people making investment decisions are rewarded for the volume of money flowing through their hands, then a growth orientation of the economy follows as the night the day. And if you allow people with excess cash to put their money in the hands of the people making investment decisions in return for a cut of the profits, then fairness goes out the window. We need a form of community or public finance. A dictatorial central government is one possible form of such community finance, but I am not convinced that it is the only one.

The second component of my idea of a fair economic system is that people who are very good at performing some valuable economic task should be rewarded by a combination of job security and/or reduced working hours but not by excess economic consumption relative to other people performing valuable economic tasks. This is to say that there should be a maximum salary which the majority of people employed on a full time basis would receive. This is not to say that anybody is guaranteed this salary. If I employ two janitors and I can easily go out on the street and find someone who can do the work of both of them in the same number of working hours, then I am free to fire the two inefficient janitors and hire the more efficient one. But if it is worth my while to hire a janitor full time, he or she gets the salary. A business could uniformly reduce salaries throughout the business in an effort to survive hard times, assuming the employees were willing to accept this reduction and not to jump ship. But you cannot say to anyone: we need you to work full time, but because you were born with the wrong genetics you can work like a slave all of your life and you will still be dirt poor.

You may say, of course that such a system would discourage talented people from utilizing their talents. I have two comments about such a claim. First, the day the you are willing to sign up to be a full time garbage man, or a garment worker if you receive the same salary that you do today, send me a note. I'm holding my breath. Second, encouraging talented people to try to use their abilities increase the total volume of stuff being manufactured and sold is an incredibly bad idea in a world running up against resource limits. We have to find some outlet for our entrepreneurial talents other than trying to sell more stuff this year than we sold last year. As Kenneth E. Boulding wrote in THE ECONOMICS OF THE COMING SPACESHIP EARTH:

By contrast, in the spaceman economy, throughput is by no means a desideratum, and is indeed to be regarded as something to be minimized rather than maximized. The essential measure of the success of the economy is not production and consumption at all, but the nature, extent, quality, and complexity of the total capital stock, including in this the state of the human bodies and minds included in the system. In the spaceman economy, what we are primarily concerned with is stock maintenance, and any technological change which results in the maintenance of a given total stock with a lessened throughput (that is, less production and consumption) is clearly a gain. This idea that both production and consumption are bad things rather than good things is very strange to economists, who have been obsessed with tile income-flow concepts to the exclusion, almost, of capital-stock concepts.

My ideas for bringing about a wealth maintaining economy (as opposed to a wealth increasing economy) may well be impractical, but I have yet to read a single line written by any promoter of the "efficiency" of capital markets that they have clue about how to bring such an economy into existence.

If I give you money, which represents purchasing power, and expect you to return a larger amount of purchasing power to me at some later date, then that excess purchasing power has to come from one of two sources:

1. Total economic output increases.
2. I take purchasing power away from somebody else.

No third option exists.

Fallacy of the excluded middle.  The third option is you give purchasing power to me today and I give more back to you over time; it doesn't come from any third party.  What I'm getting out of it is the use of more resources than I have at hand immediately.

In the case of borrowing for e.g. a house, where I'm paying more than rent would cost but I get the use of a house and wind up owning it (plus the social benefits of my personal stake in the condition of the house and neighborhood), it's likely worth it; in the case of borrowing for spinner hubs for an Escalade, almost certainly not.

No one should be able to earn money simply by virtue of the fact that they already have money.

Should people be able to earn money simply by virtue of the fact that they already have a building full of machine tools, or a house to rent?  That will eliminate investment in factories and rental housing, and you'll see everything collapse.  If you think that government can allocate investment better than private agents with their expertise, you're quite crazy.