TIPS&TRICKS: Is it always good to have many impressions? Should the goal always be to receive as many impressions as possible?

Yes, but only if your metrics are good, like your ACoS is within your given threshold, your margin. Then it's always best to have the maximum impressions and spend as possible.

For example:
If you are reaching your target ACoS, like 25%, then you are more likely would like to spend a million dollars on that keyword/search term, because you are making a profit. The more you spend, and more impression you get, the more profit you make because you are profitable in your range.