王爷 are normally brothers of the emperor, however this title has also been given to people who have done something extraordinary for the country. 中堂 is a general title of those who have the position and power to make decisions on behalf of the country. 大人 simply means people who have been accredited the position/power to work for the government, normally as the head of local government. you can also say 中堂大人.

Dimmi cara，你是在看‘穿越小说’么？= =

这都是以前的说法了，现在没有这个。不过影视古装剧的里面比较多