Is there anything wrong with "wij houden van je" because, for example, a pronoun after "van" must be stressed, or is it just a translation oversight?
Wij houden van je is not really a correct form. The form je as an objective is only used in several dialects. If you meant the second person singular, use jou.
Why is 'Wij houden van jij' incorrect?
How can you tellfrom engilsh that this is a plural you (translated jullie) rather than a singular you?
You can't without any further context, hence singular and plural is accepted.