I guess the folks on this forum are going to need some more information to answer your concern. What is your motive/objective to "stall" the process? Part of the process is to determine fit or unfit for duty, so this results could be to return you to duty depending on why your were placed in IDES? My PEBLO indicated that only two percent are deemed fit when the case gets to the PEBLO stage for Air Force cases. What more can you tell the forum?
Yes, there are many ways to stall the process. It is done frequently by people just sort of 20 YOS, who want to be eligible for CRDP. If you search the forum you will get many ideas. You make want to consult with an attorney.
I don't think anybody really has a crystal ball and can tell you when you're going to be separated or retired if that's the case. You also have to factor in your appeal time (if you do one) and your terminal leave/PTDY time. I'm going through the process now and can tell you, most people try not to give you dates and timelines because they can only control their portion of the process.