For issues
1, axis title hidden: that's chart's behavior to hide axis title first if spaces are too narrow even to show the axis labels in full. We believe axis labels, compare with axis title, consist of importance information if we need to hide 1 among 2.
2, Unfortunately that sap.viz.ui5.*** chart library doesn't have label rotation property exposed. Please allow me to introduce our vizFrame library and it comes with this property available. Relevant API doc is available on https://sapui5.netweaver.ondemand.com/docs/vizdocs/index.html#reference/chartProperty/Charts/Bar%20%20(13)/Column%20Char…
3, Showing data label of Pie chart outside: Unfortunately, this is not supported.
BR,
Chapman