Note that each transaction that affects the Customers ledger is linked to an account in the ledger, so if you edit any transaction it will stay within the customer ledger.

If you have created a "suspense" customer for the purpose of being able to delete old customers note that if you edit the transactions it will leave behind an extra transaction (with the deleted flag set) containing the original details which will not permit the original customer to be deleted.

Moving older transactions into a suspense account does not sound like a good idea to me (breaking the link between who owes/to whom is owed a debt).

Personally I find that transactions that have been edited in any way mess up my external reporting which use exported reports for the data.  I would always prefer contra entries whereby Invoices are moved by credit notes, values are fixed by Credit notes/Invoices, etc (just as if it were treeware store data).

What exactly do you mean by "tidy my customer ledgers"?

Thanks Robert