Legal Question in Civil Litigation in California

With the below exceptions, none. For the most part you could cut and paste the form interrogatories for all anybody cares. But a party is normally limited to 35 interrogatories, and in unlimited civil cases the use of official form interrogatories doesn't count against the 35. Also, special interrogatories may not have subparts, so they might be objectionable on that basis, or some other basis, even if the use of form interrogatories would not be objectionable.

The above answer is correct, but the easy way is to just object on the basis of "asked and answered..." so that they have wasted one of their special interrogatories,

None, and if they ask more than 35 special interrogatories, then they will be required to attach a declaration of necessity, which is nothing more than a mere formality in most cases.