First of all I don't have a 70D so you are going to have to experiment to see exactly how you would implement this on your camera - the 5D3 and 7D2 are 3 program modes that you can store different setting so I would just switch from c1 to c2 to handle what you are asking.
You basically need two different setups - 1 for capturing fast moving sports and 2 for capturing a large depth of field (and since you light is low you really can't do both) so
1) Your 1/1000, F2, high iso for indoor volleyball, setup is for your freeze the action
2) you need a 1/120, F11, high iso for indoor volleyball, is for your Large Depth of Field when players are waiting for a dig setup
With an 85mm lens at F11 and at 20feet to subject you have about 7 feet of DoF (so aim at the middle player and the players 3.5' on either side will also be in focus. Because your light sucks, this is going to be a difficult task as 1/120 may not freeze even slowly moving people and F11 at 85mm at 20' is just on the edge of enough DoF - a wider angle 50mm shot at F5.6 would have 10feet on critical in focus DoF and would allow faster shutter speeds.
If you set up your camera in Manual Mode to Handle #1, I'm assuming you do this already unless the 70D has mode you can program, then you can move your Selection Dial to AV (Aperture Priority) and have it jump automatically to your desired Aperture that is needed to get everything in focus - i.e. you just need to move 1 dial 1 click and it will be setup. You will also want to go into the setup menu to force the minimum shutter speed to be high enough, as mentioned above, to freeze the slow moving defensive players waiting for the spike (I'm guessing 1/200 is about correct).
Also helpful will be for you to download a DoF calculator to your smart phone so you can quickly determine what Aperture you are going to need, and lens, given your seating location and distance from the players.
Given the brutal gym lighting you are facing, and it appears your desire for both a large depth of field and fast shutter speed, you may be an ideal candidate for a Sony A7S as you are going to need ISO 40,000 to get both - i.e. 1/1000, F5.6, 40000 iso with a 50mm would do the trick.
Hockey and wedding photographer. Favourite camera / lens combos: a 1DX II with a Tamron 45 1.8 VC, an A7Rii with a Canon 24-70F2.8L II, and a 5DSR with a Tamron 85 1.8 VC. Every lens I own I strongly recommend [Canon (35Lii, 100L Macro, 24-70F2.8ii, 70-200F2.8ii, 100-400Lii), Tamron (45 1.8, 85 1.8), Sigma 24-105]. If there are better lenses out there let me know because I haven't found them.