Yes, most Highstock features can be applied to standard charts. From a licensing point of view, using features of the Highstock package obviously requires a Highcharts Stock license.

Technically Highcharts Stock is implemented as a set of plugins for Highcharts. The entire code base for Highcharts is included in the Highcharts Stock package, and you can invoke a chart using Highcharts.Chart and enable certain features that are normally associated with a stock chart.