Similar to private messages (PM), this feature is designed for exchange of messages with another member's in private. You can add multiple members and have an ongoing private conversation.
Alerts are notifications. You'll see an Alerts menu at the top right of the page when you're signed in. The menu shows you alerts and give you an option to change the alert preferences.
They are designed to alert you to responses to your threads, profile, posts or threads of interest.
Threads can be followed by subscribing to them. The subscribed threads are called watched threads.
The message posted in a thread or conversations.
A Traderji status (or profile posts) is a feature which allows you to discuss your thoughts, whereabouts, or important information with the forum members. Similar to Facebook status or a tweet on Twitter, a status is usually short and generally gives information without going into too much detail.
Visit Home 'Members' New Profile Posts to access status or profile posts.
Reply is 'Reply with quote' of the post you click in.
You could also select text from a message and right click on it to 'reply with quote'.
This link in the lower right side of the post is to add multiple quotes. You could add as many quotes as you want, and finally at the bottom, click 'add these quotes'.
These are earned based on actions you take around the forum; different actions earn different amounts of points. They're just a way to further track your contributions; your user title will still be based on the number of messages you have submitted.