1: what kind of area and depth are you guys using for your hoist pads.
I learned the hard way to spec 1" over the thickness you want (to allow for variability) and watch the contractor like a hawk. (Fortunately, I was there and caught the mistakes.) I went with 5".
Pouring pads will drive cost up without giving you anything in return. (for new construction) Due to the physics and mechanics of a two post lift, pads are unnecessary as long as you have the proper depth of slab. If you thicken the slab under the lift, and do it the wrong way, you can cause the slab to crack. (There are a lot of variables that go in to that, like reinforcing, crack control joints, how the thickened profile is done, etc.)
One thing that you should do, is talk to your concrete contractor about where your saw cut joints will be in the slab, so you can work your 2 post lift placement within those. (For example, you don't want to mount a post on top of a cut joint!)
2: im thinking the left far back area with a slight angle to allow the cars to come in from the garage door.
In addition to the comments above, the angle makes a very inefficient use of that space. You'll bet more in there if you can go in straight to the lift.
3: what kind of setback from the wall?
I calculated 13' minimum for being able to put a full size truck on my lift and have it balanced. That gives me very little walk-around room in my 24' deep garage. If you have a large vehicle, I'd go 15+, depending on how much walk-around room you want and if you are going to put a bench in front of it, etc..
