1. the generation of my parents and grandparents in the old time usually use "小人儿书" and "连环画". and now it's a little old.
i think "儿童图画书" or "儿童漫画书" is better.
2. yes, we use "派对", it's a chinese translation of "party". it's more popular in taiwan. and in mainland china, we prefer "聚会". But any chinese can understand it.