Hey Darrell, Usually if the 2" offset is causing problems you will see it with abnormal tire wear on the inside rib of the tire. "Inside rib", meaning rib closest to the truck frame will usually wear down faster than the rest of the tire. If you are seeing this wear pattern then it is one of two things or a combination of both.
1. 2" offset wheels are causing axle flex Fix: (switch to 0" offset wheels or flip your 2" offset wheels)
2. wheel bearing is out of adjustment. Fix: (go to mdalignment.com and they will have proper torque specs for axle nut. I think for super single it was 75 ft lbs with a single nut, but not sure. You may have to give them a call and you pay like $8 and it lets you access the information. )
I've had both of these issues cause problems. All truck axles are different, that's why some people run 2" off set and never have any problems and some people do have problems. I've never had an issue on a drive axle but have had my share of problems with a lift axle and trailer axles.
To directly answer your questions:
1. yes, the 2" offset wheel will cause more axle flex and put more stress on the bearings. In my opinion, if your not seeing abnormal tire wear on the inside rib, then the extra stress will not cause a problem with any of the components.
2. yes, most of the time you can flip the 2" offset wheels and they work just fine. Most wheels will clear the drum with enough room to allow the valve stem to also clear. I've done it with alcoa and accuride rims and have not had any issues. You will have to find a good tire shop that will fix the valve stem up for you. The valve stem will be on the inside and will point out through the hole in the rim. I had to go to a couple of tire shops before I found one that would do that for me. When you flip a 2" offset it doesn't give you a true 0" out set, its closer to 3/4" outset, but it does move the wheels in and seems to take care of most problems for people.
3. The track width will be just fine with any of these combinations. The smallest track width would be the 0" offset, then the 2" offset flipped, then the 2" offset normal.
I haul tankers and van trailers and I've used all three of these combinations for weights up to 80K, using the 34k axle group. Hope this helps, if you have any more questions just ask, I have quite a bit of experience in this area.