You can't really say this in English and be understood. "We see" is present, so can't happen later. "We'll see" is common, but implies a later time, so "later" wouldn't be said. And if you were going to see a person or object or movie, for example, it would probably be more common to say, "We'll go see X later" or "We can go see/do X later."
I agree with you that it must be translated with the future in English (or possibly with the past, if part of a narrative), but I do not think it needs an object, unless one is clearly implied in Indonesian. I will often use the expression "we will see," often with "later" or "tomorrow" or some other expression of time, in the sense of us coming to know the truth at some later time.
Yep agree. It uses 'nanti' which puts us in the future therefore we need our english future verbs like 'will' etc.