As to the unemployment, your contributions won't effect that, but withdrawals might. Depends on state rules and if the employer contributes a match.
You can't really contribute 100%. Some money will have to be kept out because of taxes and other employer deductions. There is also an IRS limit to 401K plans and I think for this year it's $18,000. Then depending on your income and age, you can still contribute to your IRA.
Keep this in mind before you fully commit to Roth exclusively, and living with no pay check. I was able to use a mix of traditional IRA, roth IRA, 401K to manipulate my income so that I was at the tippy top of the income scale to qualify for the Tax Saver's Credit. While it allows up to $1,000 credit, in practice, the most it every got me was about $650 because it's a nonrefundable credit and can't exceed your tax liability. It allowed me to not pay any taxes for many years, and during my low income years after I lost my job, I was able then convert 401K, Trad IRA to roth so as to pay no taxes and not have my standard deduction go to waste.

