I currently don't have internet access except through my phone, which is also how I've been downloading mods. I notice BOSS seems to rely on an internet database to sort mods. As of now, I'm unable to sort my mods properly. Is there a way to use BOSS offline? Or possibly another sorting method?

Yes, you can use BOSS offline. Just uncheck the "Update Master List" box. I think it comes with its own master list, but it's not completely up to date. It should work well for all the major mods though.

You should update the master list whenever you do have an internet connection. And maybe someone knows where it's stored so you can download it to your phone.

You can download the raw masterlist https://raw.githubusercontent.com/boss-developers/oblivion/master/masterlist.txt. It will need to be copy/pasted into the "Oblivion" folder inside wherever your BOSS install is located. I'll be uploading a page on Nexus by Friday to give people another download option.