For G325, unfortunately, you must fill all 4 pages. I believe you downloaded and printed this form from web site, so this 4 pages are independent, if you obtained this form directly from INS, you will find that the 4 pages of this form are stacked together and you must with force to fill this form. I think the 4 pages will go to different departments after you submit the form.
On your I-94, you should find its expired date. If your I-94 was came from border officer when you entered USA, this date maybe hand-written on the form, or it is a stamp. If your I-94 was came together with the approval notice if you have done the extension or change status, in such case, the I-94 is part of the notice and the expired date is printed on the I-94.
EAD application can submitted together with I-485.