I replied via email, will copy the reply here in case if someone has the same issue:
It seems that the demo content is successfully imported, but menus were not assigned correctly for some reason - please navigate to Appearance/Menus, and assign the Header menu to the Header location, Footer menu to the Footer location, then it should be ok.
Also, these may be caching issues because of third-party plugins or caching solutions enabled by the hosting provider. I refreshed permalinks and clicked Cache/Purge All, and the listings, experts, requests appeared, also the expert profiles now redirect to their corresponding pages.