All other things being equal, if I am a simulated entity, I would prefer not to have my simulation terminated, even though I would not know if it happened; I would simply cease to acquire new experiences. Reciprocity/xenia implies that I should not terminate my guest-simulations.

As for when the harm occurs, that's nebulous concept hanging on the meaning of 'harm' and 'occurs'. In Dan Simmons' Hyperion Cantos, there is a method of execution called the 'Schrodinger cat box'. The convict is placed inside this box, which is then sealed. It's a small but comfortable suite of rooms, within which the convict can live. It also includes a random number generator. It may take a very long time, but eventually that random number generator will trigger the convict's death. This execution method is used for much the same reason that most rifles in a firing squad are unloaded — to remove the stress on the executioners.

I would argue that the 'harm' of the execution occurs the moment the convict is irrevocably sealed inside the box. Actually, I'd say 'potential harm' is created, which will be actualized at an unknown time. If the convict's friends somehow rescue him from the box, this potential harm is averted, but I don't think that affects the moral value of creating that potential harm in the first place, since the executioner intended that the convict be executed.

If I halt a simulation, the same kind of potential harm is created. If I later restore the simulation, the potential harm is destroyed. If the simulation data is destroyed before I can do so, the potential harm is then actualized. This either takes place at the same simulated instant as when the simulation was halted, or does not take place in simulated time at all, depending on whether you view death as something that happens to you, or something that stops things from happening to you.

In either case, I think there would be a different moral value assigned based on your intent; if you halt the simulation in order to move the computer to a secure vault with dedicated power, and then resume, this is probably morally neutral or morally positive. If you halt the simulation with the intent of destroying its data, this is probably morally negative.

Your second link was discussing simulating the same personality repeatedly, which I don't think is the same thing here. Your first link is talking about many-worlds futility, where I make all possible moral choices and therefore none of them; I think this is not really worth talking about in this situation.