At present, Guest, the CRB does not include mere allegations, or details of police investigations that did not proceed to criminal convictions. Whether this will change in light of the Soham inquiry and Bichard report remains to be seen.

Council tax stuff might show up, if it involved a criminal conviction, but depending on the nature of the job you're being considered for, a prospective employer might consider it irrelevant. A conviction for drink-driving would eventually "expire" - in other words it would disappear from the record - as would be the case for many minor offences. I'm fairly sure this means it would disappear from the CRB file too. Certain sex offences and other serious crimes do not expire. The length of time a sex offender stays on the Sex Offenders Register is determined at the time of sentencing.

The CAB should be able to give you advice, if there's one somewhere in your area. You may find this easier or preferable to asking the CRB.