anything you install on your computer gives away the same
kind of access that installing an air program does. Is it safe: the
question really is -- how much do you trust your source?
For instance, if I'm going to download a program from the net
and install it, I'm only going to download from someone I know like
Adobe (no brainer there lol) or a site like CNET's Download.com
(which tests the programs from adware/malware) and provides a
certain level of comfort for me.
In short, if the program comes from a major company and is
signed with a verified key, then it's definitely safe to install.
If the program comes from Joe Schmoe and Joe made his own
certificate and signed his program with that, then you would
probably want to see what other people are saying about that
program before installing it.