Is it possible to change the home directory of HDP users?

[#1]

Depends on whether we are talking about under HDFS or at the OS level, but the answer to both is Yes...

For accounts under HDFS, the home directory is determined by the value of dfs.user.home.dir.prefix.

see: https://hadoop.apache.org/docs/r2.7.2/hadoop-project-dist/hadoop-hdfs/hdfs-default.xml

For OS users you can pre-create your service users before install, then set ignore_groupsusers_create=true in cluster-env.xml, and then launch the installer. The service users and groups are here: http://docs.hortonworks.com/HDPDocuments/HDP2/HDP-2.5.3/bk_command-line-installation/content/create-...