I would like to decipher this very complex halachic issue in a clear manner for us all.
Noting on the premise that we must Remember Shabbos as it says in Yisro, and although our Rabbis have connected it to Kiddush, the day must be remembered as well throughout our week, that being the case, if we have intentions during the week of work on Shabbos, although its not an halachic per se issue, it defies the literal translation of the command of Hashem, of remembering Shabbos throughout the week. (Shamai had the option of always buying something throughout the week for Shabbos and Hillel had the opinion of living each day with Hashem, as you will see this has underlining reasons for their argument about preparing work on Shabbos as you will see)
Our Rabbis have permitted us to leave food to cook (not to get into much detail) before Shabbos even though it will cook on Shabbos, as well as setting up traps and other work that will be done on Shabbos by our actions before Shabbos, there is the opinion of Shamai (Mishna Shabbat) who says that all work that will happen on Shabbos is not allowed even though we set it up before Shabbos, we don't follow this Ruling but, it's good to know that all are questions would not apply according to such ruling.
There are limitations to Hillel's opinion. If you put raw foodplace food (not previously cooking) on a covered fire (according to Rashi) it is not permitted because it looks like cooking. We see that work set on friday to activate on Shabbos cannot "look like cooking" This should be applied to all questions in our "modern" era.
Shuls have a computer that shows times of day and such, some shut it off, some keep it on. It is well understood that it was done before Shabbos. A TV in a house is something that goes on and off and therefore it "looks like cooking"
AC Timers (besides the noise aspect), on one side, since timers are clear to all and it doesn't appear being turned on, or you can say that there still is a drop of doubt and it "looks like cooking", to prove my point whenever a timer activates with guests they will always be shocked for a second, this shock has some underlining doubt of how it happened.
Computer programs and such, since they are even more complex than a simple timer they will always be "looks like cooking"
The questions can be endless. I will leave off with an example, if you had a match that moved slowly toward the matchbox on a timer or mechanical device, can you light candles on Shabbos?
On the other side of this extreme, can you light candles knowing that it will go out?
Not to shake things up, but doing an action is worse than shutting off an action as we see by returning food on a fire on Shabbos has more stringent rulings. So this should be taken into account. This is one of the reasons you can have a fire burn out on Shabbos even though extinguishing a fire is a Melacha. Timers and the like programed to do an action (besides shutting the flow of electricity) are in fact just leaving things be but, it's preset to do actions which makes it an action in the future.
I would apply the Rashi in the beginning of the third perek of Shabbos as the parameter to all these questions. Including of course Rav Moshe arguments as well as anything making noise taken into account.