Bungi, unfortunately, I'm out of the office (into London for another course) for the next couple of days.
When I get back to my office, I'll check out the legalese on some of this for you.
Any of the perfomance issues and damage to company property you have raised in your post, could (and should) be covered in your contract, and therefore your actions could be deemed in breach of contract.
In the meantime, do check out your contract & terms of employment thoroughly. If you work for a reasonable sized company, it may be worth having a quiet chat with somebody from HR.
Hope to be able to comment later in the week - unless I get beaten to it. Sorry if not constructive at present.
C
