will try having some images rescanned with a Hasselblad. Some labs here do offer that option.
When it comes to dynamic range, it's not so much the brand of scanner that matters. It's how you operate the scanner. What tends to work well, is to scan color negatives as if they were slides (make sure to scan in 16 bit depth) and then do the inversion and color balancing manually. The initial output of the scanner will quite low-contrast, but it prevents any automatic color balancing routines in the scanning software from blowing out highlights or lopping off shadow detail.
If you do analog printing yourself, you‘ll need to do dodging and burning to get the best results
The opportunities for burning & dodging are generally limited when printing at small to moderate (let's say 11x14") print sizes due to the high speed of the paper. Exposures are usually in the single-digit seconds. Flashing the paper can be very effective in flattening out highlights (with the obvious drawback that they get, well, flattened out). Flashing also has the advantage that it can be used to alter color crossover behavior to an extent. Another option is masking, but this of course is extremely time-consuming.
Am I right that the graph relevant to dynamic range is the first one in each document, the one labeled "characteristic curves"?
Yes.
I'm looking at it as meaning that the exposure has a latitude of -3 stops to +3 stops. I'm probably interpreting it wrong.
You're indeed interpreting it wrong. The x-axis is 'log exposure', not stops. Approx. 0.3logE = 1 stop. But you have to look closely at what part of the curve is actually usable:
I drew in red lines that show the approximate range over which the film can be expected to yield good/excellent results. At the left end, the range is restricted by the 'toe' of the curve where it flattens out; these are the deepest shadows and as you know, underexposing negative film makes the shadows turn into undifferentiated mush. That's what happens if you allow important parts of the scene to land in this toe region, or even to the left of it.
On the other end, the range is restricted by the crossover behavior of the film. As you can see, beyond the ca. 0.25 mark, the red curve starts to flatten off a little bit. The net result image-wise is that highlights that received this amount of exposure will be relatively cyan (lacking in red). You can't always prevent that sections of your image land on this part of the curve (brightly-lit clouds or snow-capped peaks), but it's best to prevent important parts of the scene to steer clear of this part of the curve.
As you can tell, this leaves a part of the curve that runs from ca. -2.1logE to 0.25logE, so a range of ca. 2.3-2.4logE. Divide by 0.3 gives 7.5 to 8 stops of range in which the film can be expected to yield very good results. Below that (underexposure), things will turn into muddy mush. Above it, you'll run into cyan crossover territory. The latter is generally more desirable (less problematic) than the former. Because of that compromise, people sometimes argue that the dynamic range of the film is much greater than the ca. 8 stops. Sure - if you're willing to sacrifice some color fidelity, you could allow highlights to fall in this crossover territory. Especially in the digital darkroom (a.k.a. Photoshop), it's relatively easy to correct any problems that result from this, at least for the most part.
As to Fujicolor 100, it's difficult to get good data on this since this film is available so scarcely and apparently also only in certain parts of the world. There's allegedly a datasheet for it, but I honestly have very severe doubts that it's representative for the product as it's manufactured and sold today - but who knows. It can be found here:
https://www.fujifilm.com.hk/products/consumer_film/pdf/superia_100_datasheet.pdf
Let's look at the characteristic curves in that datasheet:
As you can see, the toe region of the curve is quite different from that of Portra 160; while Portra's toe is quite sharp, the toe of this particular Fuji film is very gradual. This makes the choice of what section of it is considered usable quite arbitrary; I've drawn in a rather conservative and arbitrary red line to indicate a possible point. On the other side, it's impossible to give a good cut-off point since the curves run nicely parallel in the plotted section and seem to continue on like this possibly beyond the point where they stop. Assuming that you could at least get good results up to the point where the curves stop, the range would be something like 2.5logE or a little over 8 stops. It's quite possible that you can get a little more range from it in practice.
I hope the above shows a couple of things:
* To an extent, it's possible to derive some insight into dynamic range from a film's datasheet.
* In particular, the datasheet sometimes/often shows what kind of penalties can be expected when trying to use the film beyond its best usable range.
* How big of a dynamic range you attribute to a film depends a lot on how much you're willing to sacrifice in terms of image quality. This explains to a large extent why we often see dramatically different estimates from different people for the same product. My approach above is rather conservative.
In practice, the only really good way to get a feeling for whether the product works for your purpose, it so simply try it out! In doing so, keep in mind that dynamic range is not unlimited and that you don't want to err on the side of underexposure, while at the same time trying to steer clear of the inevitable color crossover due to overexposure at the same time. In other words: try to expose properly, and don't rely on reasoning like "the dynamic range is big enough anyway, I'll just overexpose by a few stops." That may work for (some) B&W film, but with color film, it's more problematic. Also, in assessing your results, keep in mind that scanning and digital post processing are a factor of huge importance. It's to an extent possible to recover some of what may be lost due to unfortunate choices during exposure (or development). Conversely, it's very easy and in fact extremely common to totally destroy an image that in principle comes from a decent negative due to incompetent scanning and post processing choices. The long & short of it is that in all honesty, the time you invest in selecting the right film for the job is likely better spent learning everything you can about color scanning and editing...