The problem is an average active member here can easily post a 7-10 (signature boys maybe 30 or more ) posts per day in different topics and tomorrow i have to check the other users participation but unfortunately I find 20 mixed old+new topics ... after few weeks you no longer need to look to the half or more (for example speculation, games and rounds, micro-earning...). The problem with the wishlist is i have to add then remove them manually each day.
A simple button which i though it is ''notify'' can end this mess (unsuscribe from this topic) but apparently it isn't working (or i still didn't figure its function)
Firstly the watchlist is theymos's solution for your problem. There is nothing else until there is a new forum. You can unwatch a single thread (top right) and make it no longer appear in your watch list if you no longer care. You can also bulk "mark as read" (top right in the watchlist) an entire page from your watchlist. That way you can pick those you care about, read them, pick those you no longer care about, unwatch them and bulk mark the rest as read without actually reading them.
You can also watch entire boards you mainly read if you dont want to miss out on new threads. As someone that from time to time has 30 unread pages in the watchlist I dont mind that much. Just read what you care about and skip the rest.
It might not be perfect for you, but thats the tools we currently have.