Hello,
Please find answers bellow:
1) You can change value of resource string with following name: blog.commentview.leavecomment
2) Regrettably threaded comments are not supported by message boards. You may consider using forums instead.
3, 4) I've checked this in version 5.5 and there is newest item on the top and the URL field is just optional. Could you please let me know what version of Kentico
CMS you use?
Best Regards,
Martin Dobsicek