Can the root hide some of the results of the above commands from a regular user? i.e. and will give different results

Normally rpm needs to run as root for packages to be installed, and other functions to be performed. It may allow some other functions to work which generally have read-only effect (for example a user may be able to list what packages are installed). If you want to prevent the user from running it, change the permissions of the executable file. If you want to let the user run it but hide the output, move rpm to another location/name, and put in its place a script that runs it at that new location/name using output redirection. For partial hiding, do the script with the output piped to a program that can filter it as desired (sed, awk, whatever).