I don't think there's much to "get ahead" for the main story. Given that the new content will very likely start on day one, it's probably a better idea to start again anyway, at least as long as you want to use the cheat mode.
As long as you don't save during dialogs and always save on the main map you should be fine but, given from what I've read, I'd say results are still mixed even if you follow those instructinos. Some people had issues, in my case it worked well, though I didn't transfer a full 0.19. save but an incomplete one. Given that they are likely to further improve the whole situation its probably somewhat safe, but there's no guarantee.
I don't really see a reason to play the full game again right now anyway, so you may just start Consuela's story now (all her story requires is 7 charisma and $6000) and play the rest when 0.20 drops. In that case you have a very slim save and can enjoy the new version once it's out.
Aqua will get some content at some point, but I'd expect that to be one of the very last things, unless it's some kind of surprise update. Next to pregnancy DC hinted that he wants her to have some fun with the seasucc, too.
Loli stuff won't happen though, thanks to patreon. DC even refuses to introduce really flat chested girls because they could be considered "too young".
