Combine replies in the Message Centre + Reply all feature

When using the message centre, I noticed that it makes a new thread each time I message someone / get a reply back. I was wondering if it's possible to make it so that the thread remains in one message so I don't have multiple of the same thread in my inbox? 

Also I noticed that if I get a message and multiple people are added to that mesasge, if I hit ‘Reply’ it only replies to the person that sent the message and removes everyone else from the message. There should be a reply all feature as right now I have to make sure everyone that was in that thread is added back into the message before I send. Overall, a little update to the message centre would be lovely!