I'm only at 200 and even getting that many took quite a bit of work. Each render takes 10 minutes to process, but that's not the real issue. I'm trying to do everything to the highest standard. I'm maybe a bit OCD when it comes to setting a scene up. I want everyone to say "Wow, what an exciting premise! None of the characters are clipping! They're all posed so well! Good lighting! Good writing! Nice animations! Etc... Etc... However, I'm concerned people will pop open version 0.1 and say "Oh... It's only 30 minutes long, 2 star rating(even though it took me quite a while to make).
Share it when you feel like it's ready to be shared. First impressions are literally everything in this space. This is the one time you aren't going to have pressure of a release date hanging over your neck, so pack as much as you feel you can in. 600 is a decent first release, but with more VNs coming out at a higher quality, it might be smart to make it a bit longer so it leaves a bit of a stronger impression with potential players. There's a few new AVNs dropping 2000+ render releases from the jump, and while the quality and Engrish are often present, it's slowly becoming the norm.
It sounds like you're working at high standard, and your English seems more than passable, so I'd probably guess that your work might be a tick above the rest. For reference, my new VN's first release was around a 1,040 renders, which is around 2.5-3 hours of playtime, depending on your speed. I'd consider my stuff on the higher-end level of the spectrum (don't want to come off arrogant or anything), and I peaked at around $750 before dropping back to around $400 after the month ended. That'd probably sit on the higher side of first releases, though, so I wouldn't expect that much. Unless you're working with something pretty high quality (hard to gauge without seeing the quality of your work.).
Not sure the game would have a lot of financial support up front, but I don't want to include anything that would hurt it in the long run. Atm the game is exactly what I want to create, so no worries about that. Harem games are right up my alley anyway. I'm just worried about harsh reviews and comments. I might have to get used to some criticism when I launch.
Money shouldn't be your focus at this point (nor should you quit your day job yet.). But I think you need to understand that no matter what you do, someone isn't going to like something about it. You can't and shouldn't worry about a vocal minority whining about things they don't like. If they have valid criticisms that seem to be repeated by others, then sure, start looking at ways to fix it, but do you. The only thing that's going to hurt you in the long run is saying you aren't going to do something and then taking it back and adding it a few releases later. You're going to attract who you're going to attract, and to that extent, it's nigh impossible to predict your audience.
Watch out for the fake harem clowns, though. They're loud and annoying (almost as bad as the Anti-NTR crowd), so just have your ignore button ready.