Reddit's threaded structure tends to water down discussions, splitting them up into numerous sub-discussions, as well as making it harder for the reader to easily read through a topic. It's upvote / downvote based comment and topic sorting and filtering essentially introduces censorship by democracy - unpopular opinions get pushed down and filtered out, while regurgitated popular opinions consistently get pushed to the top. I'm not particularly fond of Reddit's social media like site design either.
I agree, even though AFAIK there's sub-reddit option to remove downvote option.
As for quality:
1. less strict moderation
2. spam eradicated
3. not spending massive amounts of money and effort on numerous staff, machine learning based detection systems, etc.
Pick 2
By removing signature and bounty child board, 3 of them can be achieved (or partially achieved) at cost forum activity significantly decreased.
Using Machine Learning to detect spam sounds good even though it's expensive, but it's possible if deleted posts because spam is preserved as training data, there's category option when report post and few people with such expertise.
I'm not sure where to discuss Lightning - would Bitcoin discussion be a good place? I want to start to use it to accept payments.
Not bad idea if you self-moderated the thread. You also can check
https://bitcointalk.org/index.php?topic=4638321.320, but it's technical oriented discussion rather than general discussion