Your shot would have more impact if the sun were not at the center and if the ocean and sky were not so close to equal in vertical dimension. Rule of thirds!

The danger of street muggings even in tough European cities is exaggerated. I did lots of walking in Rome, Marseilles, Naples, Palermo and other Sicilian towns carrying a DSLR and never had a problem. Nor do I know anyone else who did. Can't say the same about the Third World. Your gear should be covered by a personal articles insurance policy anyway. Pickpockets yes... but (lol) that's a reason NOT to have a small camera in your pocket.

You didn't say what lenses you have or if you expect to shoot any wildlife on your trip. For most city travel, seascapes and landscapes you only need one lens and long focal lengths are not important. On the D500 the best choice would be the Nikkor 16-80. 16mm is plenty wide. If you carried a wider lens you would rarely need it. If you really think you are going to need telephoto and don't already own one, buy the AF-P DX 70-300mm. You can get one gray market for less than $150. at Walmart. Excellent, very sharp lens and weighs only one lb. Will you need flash? If the answer is yes, carry or buy a separate unit for the the flashless D500. The RX10 IV is actually quite heavy at 2.41 lb. If you really want to go light there are many better choices.

I have my equipment insured with a personal articles policy with State Farm. As previously mentioned the annual cost is a little over 1% of stated value, there is no deductible and accidental damage of any kind is covered. I can actually well afford to insure my own equipment. There is another value to this insurance. Confronted by an armed robber and knowing that you are covered, you are much more likely to just surrender the gear and survive than do something stupid.

I tested a Nikon 20 II TC with my 300 PF and D500, including an "in-the-field AF Fine Tune. The results were hideous compared to what the naked lens can do, very soft images. I don't believe the D850 would differ from D500 in such a test...similar pixel size. Nor do I believe the later III model of the TC would be significantly different. Nor have I seen any report of the combo 300 PF and Nikon 2.0 x TC working well.

Based on thousands of birding shots, The 300mm f4 PF with the 1.4X (net 400mm) is quite sharp, with only a small degradation relative to the naked 300. In bright light, focusing on moving birds is fast and accurate with my D500. Compared to results with the 200-500 at 500 though there is a big difference. The 500 gives very noticeably sharper results than the 300 + 1.4x TC, but for many is too heavy to hand hold for long periods of time. Hopefully, for those who can afford it, the new 500mm f5.6 PF will fix this...at least partially. The 500 PF is about twice as heavy as the 300 PF.

If you shoot larger birds, the 300 PF on a DX camera such as the D500 is close to ideal. I rarely use mine on my full frame D750, only in very low light. For small birds you really need a lens with focal length 500mm or greater.

By the way, the 300 PF is NOT "AF-P." AF-P refers to the focusing technology and Nikon's two 70-300 AF-P models (DX and FX) are currently the only telephoto Nikon lenses with that designation and technology.

Fantastic shot. Very cool.

Sensational shots! I'm envious.

The 18-140 is a good lens and sharper than the 18-200 but (a big BUT) it is soft at the long end and noticeably loses contrast there. Buy the D7200 body but do yourself a favor and also buy the 70-300 DX AF-P lens. Sharp right up to 300mm and lightning fast AF. You can get it for $144 from Walmart.com. Gray market but at the price still a super deal. If you ever have the bucks you can later get the superb 16-80mm DX lens. Overpriced new at over $1000. but I have seen it refurbished or used for as little as $700. It goes wider to 16mm which is important to me and may be to you depending on what you shoot. I would ignore advice to go FF until you really, really need to...if ever.

I shoot the D500 too with great results but I have an issue with your math. The overall sensor sizes of Nikon's 24 MP and 21 Mp DX sensors are very similar. To the extent they are the same that would mean the areas of the individual pixels would be inversely related to the Mp. (since total area = constant = Mp x individual pixel area. ) So the individual pixel areas on the 21 Mp sensors would be 24/21 = 1.143 times larger than those in the 24 Mp sensors. That's about 14 % larger in area. Some folks seem to know the exact dimensions somewhat better than this estimate and quote 16% bigger rather than 14%.

https://cameradecision.com/compare/Nikon-D500-vs-Nikon-D7200

In either case hardly "almost twice." But enough for a small advantage in low light performance.

You seem to have a nasty arrogant attitude about this. All caps? "Fella?" "Duh" Maybe you'd be happier on Twitter.

"Beginning of their development?" Really? I bought my first mirrorless digital camera in 2000. Or i should say Bill Gates bought it for me. But that's another story.
I think you mean mirrorless ILC.

No brainer. Buy the Nikon 10-20 AF-P VR. Yes, it has VR which all or most of it's competitors lack. The VR largely makes up for its slower speed. The Tokina wide angles are far better built and maybe slightly sharper but more than double the weight. For a lens which you will most likely rarely use, weight is particularly important. Thinking about eventually going full frame? The Nikon 10-20 is entirely functional as a full frame ultra wide angle lens between 13 and 18mm! That is, no or insignificant vignetting. I had the Tokina 11-16 for a while but I bought the 10-20 as soon as it came out. I still use the Tokina, mostly for interiors. I'm going to China in a few months with the full frame D750 as my only camera. Taking the Nikon 10-20 DX for ultra wide angle. At 8 ounces I will hardly notice the extra weight.

There are no Nikon lenses the D7200 can use that the D7100 can't. Possibly thinking about AF-P lenses. Fine on my D7100.

For those interested in these amazing birds there is a magnificent book based on the author's ten years tracking and observing Peregrines in the wild. "The Peregrine," by J.A. Baker. Some say this book is the finest account of any non-human creature ever written in the English language. No photos but beautiful prose.