Yes, the rule of thumb is that you give the remedy more often the more acute the situation. There is the issue of dose and also potency. Higher potencies would be taken less often than lower potencies.
As for how many pellets to take, there is never any reason to take more than one pellet for one dose, when it comes to potentized remedies. Remember that this is not a material dose of a substance that would require a certain amount of physical substance. The amount you take at one time doesn't matter. If you take one pellet or the whole bottle at a time, you're getting one dose! So you might as well take just one pellet, but that's hard for many people to understand how one tiny pellet could do the job, so they can take a few.