Thoughts and questions time.
1) Off-Road capability
I really dig this vehicle. I bought it as a safer alternative (for the rear seat passengers) to a Jeep JKU Rubicon. I had the intent to immediately lift 3" with Icon stage 2 and put on 285/70 17s. I decided to wait on the modifications, and test what we could do stock. Turns out that 2 years in, we have only had to turn around before we were ready once, in Moab. That was Top of the World, and we made it all the way to the series of ledges at the proverbial 'top' before we lacked enough departure and breakover angle to continue without damage. (I elected to not stack rocks...that would have been a LOT of rocks, ha). Otherwise, we have always been able to just GO when the mood strikes, and haven't looked back. We've also had pretty much zero trail damage, and we've seen some really cool places that we needed pretty much the full capability of the TE to get to (locking rear differential).
2) Utility
We've done several multi-thousand-mile journeys in all kinds of terrain and weather. Carrying our family, plus supplies, gear, snowboard, bikes etc. This latest trip was the first excursion with 4 bikes, and with this we've pretty much reached the limits of what the vehicle can carry without too much compromise. The rear was sagging 1.5". Handling was still ok, but the added weight and distribution of such was noticeable. We never dragged the rear (other than the mudflaps) even on a fairly steep and slippery climb on a particular switchback on engineer pass. We have our system down pretty pat, carrying all our gear, supplies, and it is a comfortable ride.
3) Bike rack
ISI makes a fine product. George, the founder, used to live in our neighborhood in Dallas. Now in Australia, he makes a bike rack designed expressly for off-road use, with ample departure angle, robust construction, and smart system features. I like the rack. I'll probably purchase the additional high-clearance 2X base for more departure angle with 2 bikes (for when we don't carry all four and need the additional clearance)
4) Engine
I can honestly say that I've never felt the vehicle is underpowered. I know that some people feel the engine is a bit less than ideal, but we're loaded up, pulling steep grades, climbing, passing, etc., and with rpm, the power is there.
5) Tires
I put on BFG KOs within a couple of weeks of purchase. I'm starting to get rubber cracks two years later, but the treadwear has been strikingly minimal and perfectly even. I plan on new tires before the snow/ice this fall/winter, and 50,000 miles from these tires has been completely trouble free. No punctures, no flats, no issues whatsoever. While we don't get snow where we live, we spend a few weeks in Colorado/NM each year, with occasional ventures into Utah/Wyoming/Idaho, and the snow/ice performance has been decent. We did get temporarily stuck during whiteout blizzard conditions in December in the panhandle of Texas, but we got out with a couple of guys pushing, and used a snatch strap to recover their vehicle up an embankment from an access road onto the highway. I chained up the morning after and made it to our destination, recovering a pickup along the route.
I plan to go with BFG KO2s next. I observed a LOT of these on jeeps in Colorado last week, and I have read many reviews indicating better snow/ice performance. Now the question is whether I lift and go with taller tires...
6) Necessary / desirable modifications
I don't see it as truly necessary, but I think the additional clearance, better handling of cargo weight might be something I go for now after reaching the practical limits of the stock vehicle suspension. I am thinking the Icon dual rate springs in the rear, to handle the additional weight of the bikes and gear. I was initially interested in Icon stage 2, however, I'm not interested in rebuilding shocks often. With this in mind, I'm researching OME new coilovers now, as I'm not looking for a racing performance, but rather durability and better performance for more 'overloading' type offload, with better load-carrying and handling characteristics. I actually don't really want a lot of lift, but I might go to 33" tires if I can get them to work with 2.5". I don't want to limit my down travel any more than necessary. The trick will be finding a balance for the front lift height to retain the slight factory rake with heavier dual rate rear springs. Icons are 3". I definitely do NOT want a level stance when empty of cargo. I like the functionality and utility of the rake and when we travel and offroad, we are loaded, so I want to make sure that with the bikes on back we aren't sagging.
It seems you're on the same modification route I was on after we purchased our '14 TE. We put KO's on it with under 500 miles on the odometer after we cut one of the Dunlops down on it's first trail. We went with 275/70's since we could run them without a lift and not experience any rub. 
