Accounts records link the way the rest of the application does. A GL batch shows where it came from — the document that created it, or manual for your own journals — and a reversed batch and its reversal link to each other. A journal entry opens its batch; a reconciliation opens its statement; a bank opens its account in the chart. From any total in the reports below, the path back to the individual postings is the GL Statement (7.10).
The reports in 7.10 all export to spreadsheet, CSV and PDF within the usual caps (1.3) — the Trial Balance, Profit & Loss and Balance Sheet are the prints an outsider (your accountant, your bank) will ask for. Attachments — a bank mandate letter, a signed loan agreement — live on the record itself under 1.9's rules, visible to exactly the people who can see the record.