This seems like a good approach (acknowledging it limits you to only comments from reddit/twitter users). How do you embed the posts so it shows # of replies?
> acknowledging it limits you to only comments from reddit/twitter users
As of now, my only visitors are a few anime bloggers from my circle, all of them using WordPress. As it's not possible to use WordPress comments, I'm not losing anything besides that. I could use Disqus, but I hate it, and I think they would log-in with Twitter to leave a Disqus comment so...
As for embedding, I use Hugo's Twitter shortcode, and reddit standard embed code - as all embed are from my own subreddit, I left that hardcoded, with a placeholder title, and just change the url on the code.
Seems that Twitter embed changed recently to not show number of replies anymore, but that's alright for now. They have to click on the embedded tweet and go to twitter to reply anyway :/
I might add the webmentions thing mentioned in other comments here to show the actual replies.