what don't you like? I'm a native speaker of American English, and it sounds perfectly correct to me, though I'd probably say it more simply "Sofis doesn't need to go"
Here's a decent explanation as to why it's "go" and not "goes."
(I'm an ESL and Esperanto teacher.)
I don't want to dig into english grammar too much in a group about esperanto, but the situation is about the same in English as in Esperanto. In a clause of this sort, you use the same form as you would to give an order, the simple form of the verb.
That said, nobody would think twice about your usage in ordinary speech, but you editor would kvetch.
The verb go is in the subjunctive mood: I go, you go, hi/she/it go, we go, you go, they go. Unlike German, for instance, where the subjunctive is a bit more commonly used and also more distinctly different, its similarity to indicative in English has made it fall almost entirely out of use even when it is called for like in a sentence such as this.
In Esperanto, the imperative and subjunctive moods are both signified by the -u verb conjugation, something that works really well.
Even if the English translation doesn't sound correct to some people, (and it is correct, btw), what you really need to take away from this is that we are learning it in ESPERANTO, not English. Relax, process the Esperanto information, and don't sweat the small stuff.