I'm happy you found it helpful to read!
It might seem like a lot of inboxes, but basically most of them are just pass-through-mediums for me. I think a lot of us might have additional inboxes that we do not really think about, i.e. Facebook or Twitter. I don't do a weekly review of those, but it is important to just be aware that they exist no matter how rarely they are used.
References goes into the A-Z folder system. Depending on how mobile the references need to be I put them in the Dropbox folder. Everything else can be sent to my Storage drive. It also depends on size because large files are not really that viable to be accessible at any place and any time.
The only stuff I keep in paper is official references like taxes, letters from previous jobs, physical manuals (for example my fridge, resale value), and personal letters that are special to me. That means they exist, but I do not have a A-Z reference to them because the amount is too little for such a system to exist. It also means I almost never look at them because I have a duplicate stored on my computers.
I also bought a DoxieGo just recently. I've been wanting to avoid scanning everything at work so it'll be interesting to get one. Only issue is that I have to wait some time, sending USA-Norway ain't fast!