You still haven't addressed why the only solutions to Steam are always horrible hackjob workarounds. Why not "Would you like to update this game now?" on install, and not "updating game please wait"? Why not "Would you like to change the install path?"? Why not "An update to the Steam client is available, would you like to apply it?" instead of "Updating Steam..."?
These aren't workarounds they are options, get it through your head. You are making it sound like you have to trick the program into stopping autoupdates.
Because these would frustrate people to no end, can you imagine browsing the internet and steam pops up asking for you to accept a game update or a client update? Instead they opted for the auto-update option which occurs silently and without need for you to do anything which makes it much easier. If you really don't want an updated game, then go ahead and turn auto-updates off because they aren't forcing you to update.
my personal experience with Steam is that it's pretty unstable, & that was a recent version so IMO it could be be coded & be implemented better.
As with all things there are certain to be flaws. Steam back in the day had issues mainly concerning connectivity and updates which was annoying. Nowadays the only stability problem I have run into is that sometimes the server bandwidth is exceeded and you are unable to download a hugely popular game just after realease from the steam store, but which is usually cleared up in about 10 minutes.