All alarms have description and resolution fields describing possible reasons and actions to resolve. Please take a look.
In your first case applications inside VM demand much more memory than the VM has, so overhead is swapped to the disk. Probably VM is undersized. I would consider running Undersized VMs
report to check it and get statistics-based suggestion of how much memory to add.
Are these VMs running on the ESXi host you`ve mentioned?
Regarding the second case, do you experience the problem during backup activity? I would go to Veeam ONE Monitor and check the stats for the datastore to find out if the pikes appear periodically and if they are bound with backup activity. You may leverage Datastore Latency control
And once again, I would suggest to check alarm`s description.