You know what's missing from this advice? Technical specs.
You'll notice not a lot of made filmmakers and even DPs drone on and on about this camera, that light. Instead they tend to talk about the nuts and bolts of good story telling. It's almost like they've figured out through time and experience that it really, really matters to the success of a film.
I think this question gets answered in unique ways by individuals, not consensus.
Personally, I don't think the camera answers the question of cinema at all. In my experience, cinema actually happens outside the camera and that process begins with a pencil and paper.
If I shot a static bowl of fruit sitting on the table with an Alexa (choose your flavor) it would be the most gorgeous bowl of fruit movie that approximately no one paid admission to see. If instead I took out my smartphone and told a story around that bowl of fruit it might collect an audience.
I'll offer one more. Every Pixar movie is not shot on any camera (besides the software versions) and that never stopped anyone of their movies from packing theaters across the globe.
Story, story, story. This was true circa 1800's as it is in 2020. Give me a story, and I'll give you my $15 and 2 hours of my life.
Although I totally agree with 90% of what you wrote, I have to disagree that having IBIS would automatically deem any camera as not being professional cinema, just because the other cinema cameras don't yet have it. Noticed I said yet.
It is inevitable that in the coming years you will see IBIS in more and more systems, because overall it's a good technology. Sometimes we have to be careful to not always refer to legacy for legacy sake. Yes Arriflex and RED are the pinnacle when it comes to Hollywood-style cinema, but these systems are not without weaknesses too. Pushing boundaries is about experimentation, suspending a certain amount of disbelief, trying something new and seeing what you get. It's not always about regurgitating the same old, same old just because that's the way it's been done up until now. If the Pocket 4K came with IBIS, it wouldn't make it less of a cinema camera, in fact it may even make it a better cinema camera.
People mistake "energy" in shots as translating to handheld these days, when energy actually is derived from your subject matter. Yes, there are times where handheld supports the narrative, but it's not the narrative itself.
People lack patience these days. It's imperical and a global phenomenon. It's too much time and trouble to break out or even carry a tripod. Which I find so extremely odd as a filmmaker, where nothing comes easily and by accident. There's been a trend in cinematography these days where it's about camera and editing tricks more than good, solid cinema and storytelling. But there's a difference between, "neat" and art. Neat has a shelf life of maybe 1-2 years. Art is timeless.
Ppl are reporting that the T5 will not do DCI 4k RAW @60fps without dropped frames and then the recording will soon fail. Something to be mindful of if that is important acquisition for you.
Happily, I'm here to report that the new G-tech SSDs will in fact do the above with no issues. I got the 1TB version for about $230, and at this resolution and frame rate I get roughly 71 minutes of record time, and roughly 171 minutes in DCI 4k RAW at 24fps. Not bad eh?
Another thing I like about the G-tech is it's crush proof rated at 1,000 lbs and IP6-rated for water and dust. It's also small and light, but the build is extremely sturdy, no plastic. It's very portable, as much as the T5 or Wise options.
There is zero value with C-fast right now in terms of price per GB unless you already own some. The c-fast prices need to be driven down and hopefully as more camera manufactures adopt USB 3.1 C as an output source that will force C-fast to compete better. Because as far as form factor, C-fast cards are the more portable preferred choice with a camera like this.
When BRAW comes to this camera, things on the costs of storage are going to get even sweeter.
Mounting on top is a no-no. This needs a rod solution, and it needs more available ports to also power accesories, that will be the competition in 2018/2019.
Honestly, I have no clue why BMD itself hasn't produced an official battery grip for this thing, with it's removable battery door. I think this type of design is the way to go in terms of portability and handheld gimbals.
However, if you're near a power source, and not using a gimbal plug this baby in. Cheapest solution. No use needlessly running down a battery.