For how many years & then have a go at getting a mortgage or bank loan or bank credit. Without a credit rating you might aswell go to a lone shark. Sea.
Depends what you mean by "wiped off the system". The people you owe the money too may give up trying to get it but the fact that you didn't pay will probably be held on file. Credit reference agencies hold the info, and as football says, you will find it very difficult to get any form of credit.
Going on to www.equifax.co.uk & www.experian.co.uk will allow you to check your own records. If it is a County Court Judgment, it stays for on 6 years from when it is registered. So do bankruptcies, defaults and late payments stay up to 3 years (36 months).
All the addresses that you have lived at are linked in your credit file if you were on the electoral role so consequently they never go away. Any defaults, late or missed payments will be visible to any lender.