i suppose there are a number of solutions ... adding an appropriate group characteristic to the executables and the places apt, dpkg write to under /var and then adding users to the group...
setuid....not a good idea some sort of server that runs on the host and receives requests for software and it does the installs.... I am thinking of the situation where one has a large collection of computers with many users. It would be an interesting experiment to see which packages most users need rather than installing a huge collection of packages by default. Instead let the users determine their needs provided they can use a better tool than apt-cache search or some kind of user friendly frontend. -walter
