None of of the borrowed money would be taxable income to you when you receive it.
Loan proceeds are not taxable, if your parents loaned you money and then decided to forgive the debt that wouldn't be taxable either (it's a gift). If you are paying your parents interest on the loan that interest is taxable income to your parents.
In order to determine what portion of your income is taxable you will need to look at a schedule from the IRS. The IRS provides these updated schedules annualy and your taxable portion is based on the amount of money you make and any dependants you may have.
A 401(k) loan is not taxable as long as it is repaid according to the terms set by the plan. If the loan is not repaid, it may be considered a distribution and subject to taxes and penalties.
yes
No. Loans are never income
No, you do not have to pay taxes on a personal loan because it is not considered taxable income.
the portion of your income that is eligible for taxation
A loan from a family member is considered taxable income. The borrower can deduct a certain amount of the interest paid. The lender will have to pay taxes on any interest earned.
Home equity loans are generally not taxable, as the money borrowed is considered a loan and not income. However, there are certain circumstances where the interest on a home equity loan may be tax deductible.
A tsp loan is not taxable income unless: 1 you default on the loan, 2 you miss a payment, 3 you retire or leave the federal service before the balance is paid off. In any of the scenarios above it is only the unpaid balance that is taxable.
The portion of a persons income that is eligible for taxation
Loans are never taxable...I'm not sure what you mean by a loan refund though!