I've used ControlUp a little bit. From my limited use I haven't had any issues with it and its free for up to 50 sessions (computers) and 1 user.
It is a 0 install agent based model so as long as you have admin rights on the destination it just pushes a fairly small program to run and gather info to report back. Shut down the connection and the application stops running.
Worth looking into for what you have described you need.
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