hard links only exist if your /home directory is on the same partition as other directories , eg. in most cases it is on VPS servers. You should always put /home on separate partition, so flags like -type f or -type d will protect you agains changing anything else than files and dirs.
+1 to putting /home on its own partition.
Since regular files are themselves hardlinks the f and d flags will not protect in this situation. Regular (meaning non-privileged) users can create a hard link (and a symlink) to any file that exists on the same partition. If the original file has different ownership, that will be reflected in the resulting, newly created hardlink.
As a regular user, in my home directory I can:
1. Create a symbolic link to any file on the system I can reach
2. Create a hard link to any file on the partition I can reach
3. Delete any file in a directory I control
4. Rename any directory in a directory I control
(Points 3 and 4 are meant to counter the notion that root-owned files and directories in a user's home directory are somehow safe from manipulation by the user)
Remember that in the non-malicious user case (which is hopefully the common case for everyone) file ownership mismatch is not much of an issue. It just takes one malicious user to ruin your day (week, month, year).