Mqtt issues

1.Does the device do a http post on port 80 and send its data packet to a web server when its configured to use "HTTP Client” connection type ?

Yes. but the port is configurable

2.Can the target port be changed from 8080 to ssl 443 port

You can change it to 8080. But SSL is not supported yet

3.If a custom built socket server is required to listen on port 8080.

WebSocket is supported. Not socket server