SSH - you are mixing up ssh monitoring (when port from node properties is used) and object tools. Pre-configured object tool for SSH open default ssh client without specifying port. Tools are configurable in Settings -> Object Tools.
rest of the issues is not a bug report, we can't help you with this input, without proper details. I've already recommended you to read documentation, it's all covered there in details.
Regarding core "crash" - you need to configure logging to the file, and check why it's stopped and not starting.
System is working fine for years for our customers, in different environments, and with wire range of versions (oldest is still 3.9, if I remember correctly). But if you'll find condition which actually crash core or agents - please share minidump and logs, we'll look into it.
rest of the issues is not a bug report, we can't help you with this input, without proper details. I've already recommended you to read documentation, it's all covered there in details.
Regarding core "crash" - you need to configure logging to the file, and check why it's stopped and not starting.
System is working fine for years for our customers, in different environments, and with wire range of versions (oldest is still 3.9, if I remember correctly). But if you'll find condition which actually crash core or agents - please share minidump and logs, we'll look into it.