Sorry the tax code does not work that way. The only way you can take advantage of the tax code in that manner is to incorporate. Meaning the $150,000 is made by your business and you are an employee of your own business. Moreover, you cannot spend $30,000 on what ever you want as you put it. The $30,000 would have to be spent on legitimate business expense. If you spend your company's funds on non-business related expenses and you get audited you will go to jail or pay large punitive fines. And keep in mind when you incorporate you are far more likely to be audited by the IRS than if you are a private citizen filing your normal 1040 taxes.
The vacation that you stated would not be a legitimate business expense. If you took a seven day vacation and had one business meeting during the vacation the expenses incurred on the day you had your business meeting are deductible as well as part of the transportation; however, the other six days' expenses could not be deducted from your taxes.
The other thing to keep in mind is that when you form your own company you pay corporate tax on the money you make. And, although it may be minimal, you will also have to pay yourself a salary. So, in addition to paying corporate tax you, as an individual, will have to pay income taxes on your personal salary, and both your corporation and you will have to pay the Social Security payroll tax, which is 6.2% each. Essentially, you have double taxation for part of your income, since your corporation pays taxes on the revenue it generates, and you pay taxes on the salary your corporation pays you.
To answer your tax deferral question. Income contributed to a tax deferred retirement fund does not eliminate the tax is just defers it until you start to withdraw the funds. At that point, you pay the regular tax rate on funds you withdraw. As far the interest earned, that is tax deferred as well. Money is money, most of your gains will be capital and interest based, and when you withdraw those funds you pay taxes on those funds. So, if you had a deferred tax fund that you contributed $10,000 to, and it earned $15,000 in interest over a period of 30 years. And say in year 31, you withdraw $15,000, you will pay taxes on the entire $15,000 you withdrew. Meaning at least $5,000 of the money you paid taxes on would be considered interest. The only exception is a Roth IRA. With Roth IRAs you contribute post tax dollars, so you have already paid the taxes on the money contributed to it. Therefore, when you withdraw money from a Roth IRA when you retire, you do not have to pay taxes on it. So, the interest earned in Roth IRAs are tax free; however, you can only contribute to a Roth IRA if you make less than a certain amount of money. And if you made $150,000 in a calendar year, you would not be eligible to contribute to a Roth IRA.
I was in independent software consultant for a few years.