Destruction of old files

I went paperless 2/3 years ago and have a room full of files etc going back 10 years.  I'm trying to decide how much I can send for destruction.

I'm torn between the requirements of the Data Protection Act to destroy as soon as there is no longer a reasonable need to keep, as opposed to the Limitation Statute which suggests I keep stuff for 6 years to defend myself against negligence claims, and as opposed to HMRC record keeping requirements which basically mean 6 years.

So far, I've concluded that for clients for whom I've done no work for the past six years (i.e. 2003/4 year ends), it's safe to destroy because the HMRC period has elapsed as has the limitation statute, and I therefore don't reasonable have a reason to keep under the DPA.  That's fair enough (I Think??).

What about ongoing clients?  Should I be destroying their files for 2003/4 and earlier years as well?  My plan would be a quick review of each file to pick out anything of ongoing significance, i.e. permanent file items but shred the main working papers etc.  Is this sensible, or would I be best to keep it all until the client leaves?  I must admit I'm a little apprehensive about destroying older files for current clients but do I have a reasonable need to keep everything under the DPA?

Finally, what about limited companies that have been struck off - do I still have to keep?  Presumably if the co is struck off, it can't sue me for negligence and HMRC are unlikely to re-open especially if they've given clearance under ESCC16.  Is there a case for earlier destruction for ltd co clients rather than keeping for the 6 years?

I'd be interested to hear of anyone else's destruction policy.  I've contacted my professional body (ACCA) but they wouldn't give any real information - just parrotted off the limitation statute, DPA requirements and HMRC record keeping time periods (which I already knew) but refused to give me a clue as to how it works in practice and how the opposing forces can be reconciled.