Brysondad,
As to Elon being involved with Tesla. I keep a list of risk factors, there's about ten of them on it, and this is a top 3 item for me. Elon has said he will stay until Gen III is up and running. I've heard him say it several times in several contexts. Having watched him and Tesla extremely closely the past two years, I've learned to recognize a tone and phrasing Elon will use that has a striking track record of follow through. There are other items he will discuss where you can see he's leaving some ambiguity, and sounds less committed, and there are a couple of items we've seen Elon/Tesla not follow through. So Elon, of course, does not speak "gospel", but he leaves his strongest language and tone for items he is going to follow through. I say this based on observing past words and deeds. I have a very high confidence level he is stone cold committed to staying at Tesla through a successful launch of Gen III.
All that said, there's a considerable possibility Elon leaves Tesla 2018 or thereafter for SpaceX. I get the sense he'd pick SpaceX over Tesla, and any investor is wise to account for this possibility. of course, something could happen to Elon before 2018. As mentioned he'd 42, which helps, but it is a risk factor. I'm not an actuary, but my gut says under 3% (accounting for all the people that really don't want to see Tesla succeed).
Finally as to splitting time between SpaceX and Tesla, over the past two years Elon consistently said 50/50 split of his time between the two. I saw him recently asked again about how he divides his time, I believe it was his Q&A in Norway. He said it's been more like 60 or 70% Tesla of late (I believe he said the past year). yes, I did see the 60 minutes piece where they described 3 days at SpaceX headquarters and 2 days at Tesla HQ. That may be so, but that does not mean he's dividing his time that way... clearly he does not need to physically be at Tesla to work on it. And, of course, 60 minutes may have gotten it wrong or oversimplified it... they also said he spends his weekends with this kids. I doubt there's more than a dozen days a year that Elon doesn't put some hours into these companies, let alone every Saturday and Sunday.
as to your 5 items, I'll just add some thoughts on the first 2, you've had plenty of replies on these.
1. China demand. I highly recommend this thread on TMC specifically on the topic,
China Market situation and outlook
read through it, pose this question to them. while anyone saying anything about demand in China has a somewhat speculative nature, my recollection of that thread was a level of digging and collecting information for their speculation unlike anything else I've seen on the web. while these may not be all verifiable sources, off the top of my head, I recall, 1) reports of store visits in Beijing and observing store traffic 2) feedback from Beijing store employees on orders (of course, again, taking poster's word), 3) monitoring and links to popular Chinese websites, message boards, 4) self-reporting of placement of orders, 4) links to articles, comments about positive reception of Tesla's pricing strategy, 5) descriptions of the stunning praise of at least one apparently very influential high tech leader.
add to this the fact that the Mercedes S class sold over 30K units/year in China at a starting cost of $200,000 vs. $120,000 for the Model S, and while not a certainty, I think a very strong showing in China is more than blind speculation.
2) Model X, timeline, falcon wing doors: timeline... Tesla slipped by about 2 months on the Model S. while ultimately not making any difference, at the time this was watched with much scrutiny. there was some justification for this... Tesla had to ramp up without running out of cash. Model X is a completely different story. Slipping a couple of months will mean nothing to the ultimate success of the company as they are not in jeopardy of running out of cash. As to the year or so delay we've already seen in the Model X. Why not? they are supply constrained on the Model S, why not take one's time ensuring the best execution on product number two when doing so will have 0 impact on sales; that is, if there's only supply to deliver 35K Model S/X this year, 35K Model S or 20K Model S/15K Model X has no benefit, but sacrifices the opportunity to make the Model X that much better.
there is some risk on execution with the Model X. it's quite important to deliver a car as winning as the Model S in order to solidify brand image and sales. it's been about 2 years since the prototype was revealed, and we know there are some substantial changes being made... we just don't know what they are. this could be a positive, but, of course, what Tesla sees as improvements carries some risk of not matching overall consumer sentiment. we're likely to see something in the next 4 months or so, and I do see it as a bit of a risk. while I'm confident the performance will be there, style is subjective, and I don't take for granted that they nail this one.
as to Falcon wing doors. added complexity, yes. just for sizzle like the door handles, no. Tesla has repeatedly said the very practical reason for the falcon wing doors, to allow markedly better access to back rows, including the ability to stand up in the back of the car. I've not had to deal with putting kids in their car seats, but apparently it's a pain in most vehicles. the Falcon wing doors have a functional purpose. it's also worth mentioning, that they are designed to actually lesson the amount of space you need on either side of the car to get in and out. IIRC, if you can get your body between your car and the one parked beside you that is sufficient room for the doors to open.