This is not supported in the mendix cloud, you cannot connect to your runtime other than by https. Mendix cloud v4 complicates this even more, as you may have multiple runtime instances. How are you going to address the correct runtime instance?
We do plan to provide support for new relic and similar tools on mendix cloud v4. If you are on v3, or do not want to use any of these tools, creating your own request handler providing relevant monitoring info is probably the easiest solution.
I'm not sure, but these are my (short) thoughts:
1.) Probably not, only if Mendix is willing to show this. Since there is no Cloud API for metrics, I doubt you can do this
2.) Are you sure pinging is the right way? Technically when your app is not running, you get an error page, so the ping will succeed, and your healthcheck will pass. A possible solution could be to create a custom errorpage, and create an account on uptimerobot, which can check for the keyword. If the keyword exists (ie the app is down) a notification is send. However, this is only if the app is down. For normal monitoring (ie CPU usage is high!) You'll need to check the MxCloud environment.
I wonder if we can revive this conversation. I have the same need to monitor multiple Mendix applications. I would like to know not only the health of the runtime environment, but also receive information about critical errors which are happening in the application. I understand that there is Splunk and AppsDynamics available. Are there cheaper options? Did companies build their own monitoring solution? Maybe using Mendix?