Am i correct in the fact i cant delete a file in the develop module. Sometimes i miss bad shots in my tagging and want to delete them while editing, but seemingly have to back to Library and then back to develop to do this.
Normally, this should work the same way as in library: Press the backspace key and LR will ask whether to delete the active photo from the disk or just remove it from the catalog (same dialog as in library). The only exception is when you are in the local corrections and have a correction "pin" seleced - backspace will then delete that correction. With some local corrections, backspace won't work even if no "pin" is selected - in this case just press escape to leave the local corrections before pressing backspace.
In addition to the backspace key, you can also use the "Photo" menu or the context menu. Note that the context menu on the film strip allows to delete multiple selected photos at once (the others and the backspace key only remove the active photo).