Yea, sweet love is basically a set of additional h-scenes with each of the main girls.
assuming "these translations" means "random VN or Anime translations", then it is not uncommon for it to be done even by people that do not qualify for N5 level.
If you are asking within the context of this particular VN and SweetLove, I would say that N4-5 is enough. There is more sex than language.
I would personally not recommend translating anything the length of a VN until you are at least N3.
If you want to start TLing something simple, and you aren't quite N3 yet, start with easy manga / doujins and work your way up from there. VNs are very lengthy, so even if you do find one that is easy enough that you won't need to look up every other word, the sheer amount of text will become a huge hurdle.
As someone who started TLing VNs at about N4, I can attest to it being quite exhausting, trying to TL a VN with that level of knowledge.
@ShinRaikdou Yeah, I know about that project - I agreed to share our TL with MrComputerRevo, to prevent MoeNovel cancer from spreading to Vita. But I've spent far too much time on KonoSora already and I don't even feel like translating a short, fanservice~y Sweet Love patch. Guess what I think about the prospect of translating an entire new route... >_<
I wouldn't use JLPT to measure that. It's not made with reading VNs in mind, so each level covers some things that will be unnecessary, but misses actually useful stuff (for reading VNs, that is). Like 触手. You can't read any fun VNs if you don't know what that means.
Jokes aside, the best measure is your reading skill. If you can comfortably read the VN, you should be able to not-so-comfortably translate it (since the latter is always more difficult). Well, at least most of the time. Of course, your writing skills also matter quite a lot - even N1 means nothing when editors can't understand your writing properly.
VNs are relatively hard to translate (even a crude porn VN will be more difficult than equally crude porn manga), so they aren't the best for beginners. I kinda learned this the hard way (though I was only going to TLC KonSora, I had no idea that original TL was unsalvageable... >_<).
I'd recommend practicing on doujin RPG games and such - like stuff made in RPGMaker. There are some decent titles out there, and they usually have rather simple writing and only use dialogues that are far easier to TL than narration. They are on a completely different level than even a relatively simple VN like KonoSora. Also, they can be easily hacked and patched - RPGMaker Trans is probably as noob-friendly as such tools can get. Even I can use it.
...
I-It's not that I'm getting distracted by thinking of translating something with interesting stuff instead of focusing on KonoSora, baka!
