One of my favorite romance VN is Crescendo as well^^
Umm, I'd say I'm about close to N3 level probably. I think I know a couple hundred kanji, but not sure what the exact number is... I might recognize more. It depends on how difficult the reading material is, and I do use text hooker to help me look up words I don't know. My progress sounds similar to you though, especially on more difficult VNs... even though it seems like I should know the grammar, and the vocabulary used in the sentence, I may still not totally understand what it's trying to say still... so yes, it can be frustrating~. There's a VN I'm reading right now which seems to be more beginner level, so I don't encounter that problem nearly as much with the harder ones, and can read way faster without having to stop a lot.
Also, someone told me not to obsess over one sentence too much if you at least understand the gist. The point is to keep reading as much as you can to get more exposure and practice.
Well, it seems the thread Fiddle pointed you towards is catered more to help people who are trying to Translate something on their projects I think. It looks like the thread you linked is Pinned, so yeah, you could probably revive it even if it's dead. It's worth a try, someone may help you if they see it^^