Hey, @joshuawilliam! Welcome.
In my opinion, leaving Roam is always a good decision and moving to Obsidian is probably your best choice.
Migration
The serious pitfalls are those situations in which Roam uses {{<stuff>}}. All those blocks and gimmicks and embeds will be lost.
Another annoying thing is the way Roam exports long-form text. Due to its outliner nature, every line comes prefixed with a dash.
Other than that, the Markdown Format Importer plugin will do its thing and you probably won’t face any issues.
So, to answer your questions:
Pretty easy.
Once you have all the notes inside a folder, I’d say “Almost instantaneous”.
Oh yeah. I don’t know how Roam’s graph is right now, but Obsidian’s is DA BOMB.
The basics will take you a long way. Just make sure to use [[wikilinks]] and/or #tags and your notes (and graph!) will inevitably gain some semblance of structure.
I’ve been using Obsidian almost from day one, so I’ve had the opportunity to absorb its features as they were implemented. Like my personal note taking system, my use of a certain tool evolves organically. If you can spare the time to explore the app and experiment with the way you take notes, you may even do well without tutorials and courses. Otherwise, yeah, watch some videos. There are always some nice ideas to take away.
Some unsolicited remarks
Portability and freedom
One of the many advantages of a flat-file, plain text system is that in the worst case scenario, you can accomplish almost anything with RegEx or basic scripting. For years, now, I’ve been manipulating my notes like that, be it to join them, split them, sort them or restructure them. Even if you don’t know RegEx or don’t know how to code, the Internet and the community are here for you.
Future-proofness
Ten or twenty years from now, you may barely remember the apps you used, but it’d sure be nice to have your notes with you.
If Roam were to disappear right now, you’d be left with your {{-ridden exports — or nothing at all.
However, even if every copy of Obsidian vanished from the Earth, all your local .md files would still be usable. Every link and reference would still mean something, even if took you some manual searching.
In conclusion
- Be sure not to sacrifice the most important things — your notes — to some revolutionary-shiny-new tool.
- Roam is impressive, yes, but you should leave.
- Obsidian is my favourite app right now. Of course I think you should try it.
- Make lots of backups.