That is interesting. The engine support bar that you got is different than mine. Mine has a channel that the hook goes through and then a big washer that supports the wing nut on top but instead it looks like that one has the a sliding bar that moves over the middle piece that is supported by the legs.
Anyways I wouldn’t trust the tiny chain to hold the engine in place. I would rather put the hook through one of the back engine eyelets directly to hold the engine in place. Once you have the oxygen sensors out of the way and disconnected, get the engine support bar in place, and it is time to lower the subframe.
For taking bolts out of the rear of the subframe I used your picture but made a few changes.
http://i284.photobucket.com/albums/ll37/Jimmybones777/939033173_zps59b47ed9.jpeg
First, the red arrow that is crossed out is pointing towards the transmission mount so that can stay in place.
Second, the green arrow points to the back main subframe bolt that has to come out with the two other bolts that you had red arrows pointing towards.
Third, the yellow arrow is where I would support the subframe with a floor jack and a block of wood while removing those three bolts on each side.
Fourth, do the other side and then move to the front of the subframe.
Once you have the back of the subframe lowered lets move to the front.
http://i284.photobucket.com/albums/ll37/Jimmybones777/mount1_zps566ef4c4.jpeg
First, you will have to remove the two sway bar nuts that are circled in light blue so that you can pull the sway bar down a little bit.
Second, pull all three bolts that are circled in a darker blue.
Third, leave the nut that is circled in red alone unless you are also replacing the engine mounts.
Fourth, crawl back out from under the car and lower the engine and transmission with the engine support bar so that there is a pretty good gap between the subframe and body.
Fifth, it is time to remove the downpipes/cats. Good luck.