PEM should be correct. I'm not sure then! Are there no other errors in the log? It may be time for a network trace.

Scott, the SSL error is fairly generic. Using REDEBUG as suggested in one of the comments might give you more info. Otherwise, a network trace would be the ultimate source of truth in terms of why the SSL handshake is failing.

As for the server unavailable error, I think you should review the instance's audit log and CSP log to see why that's happening.

It's tough to say without knowing your config and what exactly was done. For the second error at least it seems reasonably clear what could be causing it, maybe that will help to resolve the first error as well? I'm not an Apache expert so take my personal advice with a grain of salt, I just know that many people have found Mark's article to be helpful.
 

https://stackoverflow.com/questions/24060620/error-starting-apache-httpd-configuration-error-more-than-one-mpm-loaded

Hi Scott,

Did you look at Web Servers for UNIX, Linux, and macOS? That page explains how to configure Apache to serve CSP files.

I'm not sure what you mean by calls to the management portal. If you have the standalone Apache / gateway set up appropriately, you can serve the portal through (presumably default) port 80, ex. go to http://<hostname>:80/csp/sys/UtilHome.csp, rather than attempting to use your private web server port.

Really the independent Apache is the main piece, you can consider the standalone web gateway to be a module on that Apache web server.

Hope that helps.

I'm not sure how exactly you are planning to connect or set up these machines. If your requirement is to avoid the SMP and you can use csession to access terminal, you can use ^SECURITY or Security.Services methods to modify the services. Perhaps those are of use to you?