Positive libertarianism?

Assuming actually getting a job means that one is in no need of welfare benefits but allowing young people to live independently, let's say that people under 25 who live alone/ away from home automatically receive £250 per week until they get a job.

Let's call this the Independent Living Allowance. 

In order to have a negative income tax for low earners, as soon as one starts work they receive £80 to £120 a week or around a third the average (mean) wage. For argument's sake lets say 18-21 get £82, 21-25 get £112 and over 25's get £140. This money is paid until the person's death, so effectively acts both as a state pension and unemployment benefit as it is still paid if one is fired from or leaves one's job.

This reasoning is actually consistent with libertarianism in general and Objectivism in particular. It also allows young people to live independently without poverty or exploitation. Under 18's may have to apply but they would receive this if they are without or wish to divorce their parents and live on their own, whereas for 18s and over this is automatic and extended beyond 25 for those with severe learning difficulties.

The only proofs required are age, employment and living status, and the diagnosis of a learning difficulty. Those facing financial difficulties or looking after children or relatives may apply for housing benefit, tax credits and Disability Living Allowance.

As a corporation is not a person, Corporation Tax would be set at 35 to 37% with income tax set at a flat rate of 34% for almost all earners. With the subsidy in the form of the Universal Income slash Permanent Jobseeker's Allowance (I'm not really sure what this would be called) the real tax rate is much lower for workers on below average salaries. Further, to combat inflation the tax rate for very high earners (say half a million a year) could be as high as 98 or even 100% with or without the removal of the subsidy. Having a high income tax also allows for tax evasion.

Obviously, people who still live with their parents or who don't work won't get anything and Jobseeker's Allowance is still available for those who are looking for work (over 25) or studying full-time (over 18) at the same rates as the income tax subsidy.

Addendum: a citizen's income starting at 16 would be simpler at £80 per week, alongside an Independent Living Allowance of the same weekly amount up to the age of 21. Jobseekers Allowance can be applied for afterwards and is the same as the Income Tax Subsidy, again £80 per week, given when a citizen starts paid employment.
Having a private pension could be argued as betting that one will live for another week/month/year, while a state pension technically required the government to bet that one will not live for another week/month/year.
There is also the principle of "no taxation without representation", so if one disagrees with a government one can stop funding that government by no longer working.