Some Parts can be created with a single features, while others demand more features - there is really no general rule on how to think. Some believe it is best to keep parts as "compact" as possible (with few features) which makes it easier to edit those few features, while ohers think that more features makes it easier to edit!
For a very large assembly file that contains tens or hundreds of thousands of parts, the complexity of individual parts can (in theory) affect the performance of the file.
The beauty of IRONCAD is that parts made with many features are usually still quite easy to edit and change, no matter which previous experience of IRONCAD that you have. There are also many smart tools available to make it easy to change several features at the same time - in more than one part - even if there are no constraints used between the parts or features. Multiple Sizebox and Shape handles can be reached by holding down the [Alt] and [Shift] keys while clicking with the left mouse button. Dragging one handle will edit all the other handles at the same time!