In all actuality regardless of whether or not it's installed for use by a restricted user or not is irrelivent. Once the product is installed any process it spawns can be set by the developer to run as the LocalSystem account. This account (a non-interactive account so you can't log in with it) has more privileges than the Administrator account when it comes to the local machine. Therefore it could remove your admin rights and the rights of all users preventing you from ever logging in again (well you could log in again with the right tools and some knowledge of Windows authentication methods and SIDs). Although as the name implies it does not have rights to access anything off of the machine i.e. across a network.

Also when dealing with XP Home all users by default are considered to be Adimins by the OS. And in the case of Windows 95/98/ME there is no such thing as restricted rights. These OSes do not offer file level security due to the fact that they use FAT16/FAT32 instead of NTFS for it's file system. So the only way to protect yourself from snooping and tracking by an application is to only use apps from companies you trust. Even then however one can never be absolutely sure that your habits are not being tracked and sent elsewhere unless the code is independantly evaluated. I suggest reading any software's End User License Agreement and Privacy Policy. Despite how gouge your eyes out boring that stuff is, it's your best bet at knowing what a piece of software is going to do on your system. Any reputable software developer will be straight forward on what it does in these documents. If the documents leave you going "Well that tells me nothing" then it should raise a red flag that you shouldn't run their software.