Eric

As said in other places: 
 
The lenses are close in end results, but they are different enough that it should be fairly easy to pick one over the other depending on your needs/wants. 
 
If your goal is optical performance, creative options, and purity of optical lens design, there is no question, it has to be the 1.4. It offers one stop bigger max aperture, which means better low light, more creative options, better blur, it also recovers better in sharpness across the frame from f/2.8 on up which means you get better balanced sharpness and contrast across the frame from it.
 
The new f/2 lens is mechanically the clear winner, although I find the aperture ring actually a bit too tight, maybe that will losen over time though. The WR is welcome to keep dust out of lens and body, the AF performance is marginally better, hunting is more of a body than a lens problem anyways (the body tells the lens where to go) and people often compare old firmware experience with current firmware experience instead of comparing actual apples to apples. 
 
A lot of the reviewers make money when people use their "Buy now" links. Therefore, they often don't offer a clear opinion, but try to make those who don't own either lens buy at least one, and get those who own one already to buy the other as well. It's not that they are paid for the reviews or for a specific opinion, it's that they get money if any of the reviewed products are bought. 
 
I own both lenses because we go out as a pair (my wife and I) and we both like the XF35 field of view. Therefore having two of them makes sense for us and therefore we have the opportunity to compare the lenses themselves as well as the results later on. 
 
My personal recommendation: the XF35 f/1.4 is the better allrounder due to the qualities mentioned above, the XF35 f/2 is a very worthy contender if you have a tighter budget and benefit from WR. The new XF35 f/2 is great lens for everything where consistent across the frame contrast/sharpness/look from f/4 to f/11 isn't as critical.
 
The tiny problem I have with the f/2 is that even without pixel-peeping, the print results in the extreme corners I get from it, are sometimes (very rarely) not satisfactory from f/4 to f/8 – a range I use a lot for my photography. It doesn't affect many photos in a way that I notice it but it happened a few time to me now so that my first choice between the two is the f/1.4 if that isn't already taken by my wife (she has first pick of course).

I'm a bit confused, are you suggesting you'd carry all 5 lens in one go when travelling?  In which case I think the weight complaints about the 16-55mm and 50-140mm are somewhat of a mute point, as you'd cover virtually of the range above with two high quality lenses and only be losing a stop or so in the mid range and 75mm or so at the long end but also gaining weather sealing throughout.
 
My travel kits depend on where I am going etc but broadly:
city break/weekend: XT1, 14mm, 35mm and 56mm serious photo holiday/landscape trip: XT1 + grip, 14mm, 16-55mm, 50-140mm and then maybe the upcoming longer lenses.

My current travel setup is the XT1 with 18-135, 14, 35, and I just picked up the 27. On my last trip (Belgium & Netherlands) I mostly used the 18-135 and the 35 was my go to in museums and at night as well as the occasional portrait. I make a point of using the 14 a few times when I travel..great lens but I'm glad it's small as I couldn't justify lugging something larger around all day.
 
I'm looking forward to using the 27 on my next trip as my go to for street photos as I've found the 18-135 is just too big and the 35 (for me) a touch too tight for those situations.
 
Good luck with your choices and enjoy the trip! You're going to love Italy. The people, the sights, the landscape, the art, the food..all fantastic.

I've often thought that a great compact set up would be the X-E2 with the 18, 27, and 35f2 when available. That combination is not very wide, not very long or very fast, but you could sure do a lot with it. I have the 18-55 zoom which is way better than any kit zoom has a right to be. When I bought it with the X-E2 it was supposed to just get me started until I could afford some primes. You couldn't pry it away from me now, just so convenient. The only primes I have bought are the 27 and the 56.  I love the 27, makes such a compact outfit and takes great pictures. I find that the 27 focal length really suits my shooting style.

I use a Canon 430 EX (not the II version) with my XT1 and it works fine - on camera or off..manual mode only of course.