reduced Write Post screen

for a simple blog, based on user generated content, I try to bypass wordpress login mechanism, to force wordpress determine all users as a registered user (say, guest) with limited capabilities. but after that I want to reduce some services on write post screen. after this I need a write post page only contain a titlebox, editor, tag box and save button. and without other buttons (save, save and continue editing) and boxes (page status, post slug and …) I’m not a web developer but trying some changes on wp-admin folder’s files not soved this problem… How I can do this? 😉
excuse my english, I’m Iranian 😉