Just give it the name of a file to edit. 4 - A windows question. I have many files associated with emacs. Play in the registry searching for Emacs. Cautions about editing the registry apply.
Most people prefer it.
I use it for mailto URLs. The association is just mailto.bat, Windows passes the URL to the program automatically. I'm almost there. I can use gnuclientw -F to open a document. Next questions 1 - I can open several frames and it is indeed faster.