"Do you think it is better to have a smaller family?"

Translation: Myslíš, že je lepší mít menší rodinu?

[smoaking]

is "ze" absolutely necessary?

[endless_sleeper]

Yes.

[AnnaTurund]

I thought it should be "lépe/líp" and not "lepší".

[VladaFu]

You can use either the adverb or the adjective here. Both are possible.