The first 6-12 months here (during/right after the Reddit API drama) were great. After that....not so much.
Note: Edited to add to the title and replace the image link with one that won't be going offline in 2 weeks.
No, just the posts, I don't think you have the ability to block comments from one instance.
And if an entire instance is dedicated to NSFW content, the chances of missing something good are slim to none.
I use Boost, I'm not sure if it's an app feature or a platform feature.