Switching from Obsidian to org-mode - Best Approach for File Tagging?

Hey everyone, I'm hoping to get some advice on using tags effectively within org-mode. I’m a former Obsidian user in the process of switching over to org-mode, but there's so many options and I can’t quite decide on the right direction.

For my use case, in addition to task tracking, I'd like to use org-mode for longer-form writing. This can be meeting notes, video scripts, training content, process SOPs, etc. But generally speaking, I want one file per note, and I'd like to use a flat directory structure with files organized by tags so that I can file them across multiple concepts as needed. This works really nicely in Obsidian with nested tags, but I don't quite get how to replicate this in org-mode. So my major questions are:

1. Should I be using something like org-roam for this? My initial impression was yes, but in exploring that and similar options a lot of them seem to expect tags to associate with headings rather than files, which isn't what I want, unless I've misunderstood.
2. What's the best way to quickly browse, search, sort, etc individual tags? Something where I can browse through tags while seeing associated notes would be ideal.
3. Do nested tags as a concept exist within org-mode at all? For example, in Obsidian I track troubleshooting steps & resolutions within “troubleshooting/linux” or “troubleshooting/emacs”, where troubleshooting is visually collapsible, and I can look at all troubleshooting tags just by clicking that parent tag.

Thanks in advance!

https://redd.it/1wnajg8
@r_emacs