Of the four bikes in your shortlist, the Royal Enfield Himalayan 450 will offer you the most performance as well as the highest levels of long-distance capability and comfort. However, inside the city, it will feel large and a little top-heavy at crawling speeds, and its fuel economy, too, will be lower than the rest owing to its larger motor. The Himalayan 450 is also quite a bit more expensive than the other bikes you are looking at.
The Honda CB350 H’ness and Royal Enfield Hunter 350 are comparable neo-retro roadsters. It will be great inside the city, and as long as you are a sedate rider, it should be reasonably comfortable and capable on the highway too.
You will have to take a call based on how much time you’re going to spend in the city vs out on the highway, and whether your budget permits you to stretch for the Himalayan.
If you’re okay with handling a big bike in the city, then the Himalayan 450 does make for a fantastic all-rounder.
We’d recommend a test ride of these three, nonetheless, so you can decide which one suits you best.