The 1st one is possible but not in a chart. You can add a dashlet and select "Admin Latest Health & Wellness Alarms" and get a similar list in a dashlet.
The 2nd one was somehow possible in 10.6 and it was the Alerts Summary page. Not in a dashboard but you have a chart in that page and shows the number of alerts for the time range you have selected.
I haven't seen in in v11 though so maybe raise an RFE and ask to bring the missing functionality from v10.
Yeah i know about the dashlet. Unfortunelly we need more information than it gives.