Full disclosure: I am a self-admitted Honda fan, so my response will probably have a bit of bias. That being said, here's what I think.
First off, you might be the first one in this forum who's seriously shopped for the redesigned QX50. Most of us here preferred the sporty nature of the first generation EX/QX50, and will probably look elsewhere for our next vehicle purchase. So you might get some more bias from other members as well
Anyway, what matters is what you think is most important. Engine reliability, transmission type, infotainment, or interior styling/comfort? As for your points...
1. I don't think there would be much of a difference in the long term reliability of either engine. The VC Turbo is definitely more complex, but nowadays I don't hear much about engine failures in most cars across the board as long as maintenance is done. There's usually never an issue with the hard parts of an engine over it's life. It's typically all the ancillary components (sensors, cooling system, gaskets, charging system etc.) that start having issues when the car gets old. I've found on average that replacement parts and repairs on an Acura are a bit cheaper than on an Infiniti. Acura maintenance might cost a bit more though.
2. It's hard to compare the real world fuel economy of both models, as they're both pretty new. Fuelly.com has gas mileage reports from 15 RDX owners, but only one QX50 owner. The mileage number is close between the two, but more data is definitely needed to distinguish between them.
3. Infiniti says that they plan to roll out Apple CarPlay/Android Auto in 2019, but I didn't see much details about when or how. See here: https://www.motorauthority.com/news/111 ... ent-system
I'd be very wary about Infiniti rolling out a software update that incorporates the Apple/Android integration into their current infotainment systems. The automotive OEMs are very slow to develop their infotainment systems, CarPlay/Android Auto do have certain hardware requirements, and we don't know if Infiniti had designed their current system to accommodate CarPlay/Android Auto in future updates.
4. If you have the newest iPhone operating system (iOS 12), it will allow you to use Waze via CarPlay. It's not ready at this moment, but the updated Waze app is currently in beta testing for CarPlay compatibility and should be available soon. Google maps is already up and running on CarPlay.
5. I used the lane departure system probably only one time on my old EX35, so I can't comment here. I'm not sure if the new QX50 uses the brakes, or makes use of the electric power steering.
6. I also have no experience with run flat tires, but I'm not the type who would like them. I'd definitely prefer to have a spare tire handy. It's up to you really. If you get a simple puncture in the tread area, then run flat tires work. If you have some other type of tire failure, you're gonna have to call roadside assistance and wait for a tow truck.
7. I can't comment here as well.
Both vehicles are first year models, and each will have their flaws, quirks, and growing pains. The experience of the dealer's service department might be a big factor for you, as you may have to get these issues addressed. I've had experience with both brands; the local Acura dealership hasn't given me any reason to complain, but the Infiniti dealership experience was notably better. Dealerships vary A LOT
within a brand. Before you buy, see if you can get a feel for how each of their service departments treat their customers and accommodate their needs/wants.
Based on my limited experience, I'd guess that the Acura would give fewer problems as the cars get up there in mileage/age. If you switch cars at under 100k miles, then I wouldn't believe that reliability is an issue. I don't know what the sales figures are for each car, but I do think that you'll probably find a bigger online presence of the RDX owners. This does help when trying to find solutions for common problems or issues. Also, if you think you'll keep this car 10 years like the M35, you might want to get the CarPlay. Smartphone integration appears to be the de facto standard in cars for the next few years.
If you end up test driving an RDX, please get back to us about it.