It's possible indeed, using Advanced Mode you can change the chart type.
See https://docs.mendix.com/appstore/widgets/chart-advanced-tuning/ with an example changing bar chart to line (under 4).
Yes, it's possible to combine different forms of chart by using the AnyChart widget. You can feed it data, that data can be formatted in either line / bar or whichever form of graph you want.
You can use this as a reference:
Plotly multiple chart type reference