The first part of your question is about how to delist your property. You'll drop in search rankings either way, but I would snooze my listing rather than keeping it open with 8 months of dates blocked off. This means you don't appear in search results but also means you won't get inquiry questions from people you'd have to decline because they actually want to stay during your blocked dates. You can just turn in your hosting cap for 8 months.
The second part is about your SuperHost status. The metric that will be affected by not hosting is your trip count. At each SH review, Airbnb pulls 12 months of data and they require you have at least 10 stays during that 12 month period. So long as the stays you have before and after your hosting break keep you above that 10-stay threshold you'll likely keep your SH status.