Kate,
Which Goodyear tires did you get? I am guessing Wrangler HPs which are a ..... fair ... street tire but you won't be getting too far off-road with those.
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The MT/Rs that Carl mentioned are off-road mud tires and it sounds like you would have little need for them.
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If possible you might see if you can get the dealer to swap you a set of All Terrain tires. They all have a deal with a local tire company although the swapping is easier done before the sales papers are signed. At the very least the ATs will give you better winter performance.
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Everyone has their own favorite tire manufacturer, BFG is popular here but not universal (I have Kumho Venture AT-825s on my Grand Cherokee, see chart above)
Depending on how high you lift your Liberty you might need new (longer) shocks or shock extensions.
The 'discos' are sway bar disconnects. You need to disconnect the sway bar for full articulation off-road but you don't sound to be planning that either.
A towing point front and rear is important off-road so if you get stuck someone can pull you out without endangering your axles or body. (The KJ's not yours) A trailer receiver counts as a rear tow point and allows the addition of additional carriers, etc. that may be of interest now or in the future. If money is a consideration you only 'need' one tow hook in the front.
Take a look at Bill's video. The KJ got stuck because of design limitations and driver inexperience. The passenger rear tire spun because it had little traction and the standard differential will allow the tire with less traction to spin freely and the tire with traction to remain still. You can 'remedy' the open differential by applying the brakes while giving it gas. The resistance from the brake will often trick the differential into thinking both tires have equal traction. If you were just ordering the KJ now you could add the posi-traction option that does this automatically. It is not as good as a true 'locker' but is much better than nothing. The driver should also have been further to the left, ALWAYS select your line when given the chance.
While you are at it get a set of substantial rubber floor mats to replace the carpeted ones that came from the factory. Your KJ isn't like your old CJ where you could just go to the carwash with the top off to clean the interior.
I am not sure how many people in this newsgroup have experience with the 3.7 liter V-6 engine as it is fairly new but I am sure some of them know where to look and call for good information