I ride on 50" or less trails but I also go up to Berlin where it's 65" or less. So I'd like to make it wider for better stability.I know I can get spacers and get to 53.but I would like to go wider. Is it possible to get up to 56" or more with offset wheels? Or is that to much stress of the hub

[2015 Z Force 800 53/Trail EPS]

There is a benefit for having a wider stance...but after I went with the 1.5" spacers some tests and studies came out that indicated those benefits for having only 3"s more has a far less effect on CG then expected. But it does feel better..at least in my mind. 9 or 10" more and you will be where the EX is. Getting back to wheels, as long as the first number is equal or greater then the second number, you won't add extra side or torsional load to the bearing..which by the way one has already done with the spacers. I have another post where I took actual measurements of the stock wheels on a 53" machine and a +3 or a +4 wheel will add several more inches to the overall width. So with the spacers and stock wheels, right now, my outside to outside front tire measurement is about 54.5". I can add about another 2"s to that if I went with a 5+3 on the back and a 4+3 on the front. You could go to a 4+4 all the way around but you would have to keep all the tires the same...and there has been some talk about the extra width in the rear needed because of the load of the engine being...in the rear. Even or balanced traction kinda depends on load on each contact patch square inch. Some say with all the same size tires it would be out of balance and there may be some control issues with having all the same width. So..you will be safe with having 11s on 8" wheels on the back and 9s on 7" wheels on the front.

For me..I am considering taking the spacers off. I expected reduced service on the wheel bearings but I didn't expect what I am getting... greatly reduced service life of suspension bushings. 

I understand what you are trying to do but the problem is that you are trying to have 1 machine be 2 totally different machines.  The trail model if made as wide as you are looking at will CHEW through bearings and other suspension parts. In general from my experience you can get away with 2" spacers on each side with minimal extra wear.  That would put your 50" at 54".  Anymore than that and IMO you are seriously stressing suspension parts.  If you want to increase stability then there are 2 ways to accomplish that.  You can widen it like we discussed, and you can lower it.  I know a lot of people dont like the sound of that but if you set the cart up right then lowering it has a ton of benefits.  stability and handling go through the roof when you get the carts center of gravity down.  Now in doing that you need to protect the belly of the cart but a skid plat is MUCH MUCH cheaper than trying to widen the cart is.  My suggestion is put some 2" spacers on it which are pretty cheap, buy a nice aluminum skid plate (some people like the HDPE plastic ones but im just not a fan), and soften up your shocks.  It will ride smoother and give you more stability.  IMO anything else you would do will have negative long term effects on the rig.

[2015 Z Force 800 53/Trail EPS]

One other option would be to...buy a second machine...and make it an EX.