The only thing that is not 'open' is the individual record of those giving to the church.
The only one to sees it all is the treasurer. Oh, the folks who collect the plates and deliever the collections to the treasurer may get a glimpse of what's written on an envelope, or see a check, or but that's about it.
Same with my church, but I still always give cash. Mormonism made me a bit paranoid.
If you want to see the last 5 years books for our church, you just walk up to the secretary and ask. If you want further back, you have to wait a couple of minutes for her to walk you to storage.