Hey there!
We have 4 routes planned at present with the possibility that we might add more at a later stage.
Sileo will be available free of charge - during development our supporters on Patreon will receive frequent work in progress updates but as we reach milestones in development we will bundle everything up and make it available here on Itch.
On the topic of translation, we've talked about it but it won't be something we'll pursue until the game is nearing completion and whether or not we do it will depend on our supporters on Patreon both for funding the translations as well as determining what languages we translate it to. The engine we use does support unofficial translations however so there's always a possibility someone will translate it themselves at some point.
Hopefully that answers your questions!