What is the status until MTR? (According to the 485 denial notice, it should be filed within another 25 days).
unless u have another non immigrant status ( like valid H1 ) you are out of status from the date of the denial letter. you are no longer in AOS.
Filing MTR does not automatically put you back in AOS. Only on a successfull appeal , you are back in AOS. untill then either you are in the non immigrant status or invalid status.
What is the status when reopened?
you are back in AOS. your AOS status ( from the date of denial untill MTR is succesfully processed ) is returned retroactivily to valid state.
What is the procedure for reopening?
get the denial letter and file I290 ( i think ) to reopen the case.
What is the Validity of EADS and APs?
EAD/AP become invalid on denial of AOS irrespective of MTR.