Please find below your answers:
1.is the possibility to turn on/off graphs and in the chart via e.g. a checkbox which is displayed next to the chart
2. can I e.g. display a bar chart as an overall to a two line chart?
Yes, using dual axes
3. can I display more than two lines in one chart, with one timescale?
Yes, just drag multiple measures on extreme left and drop it:
example1_v10.2.twbx 2.4 MB