Those sound pretty normal for a game that is 1+ years from release. I don't think any of that implies they are early in development or that it's 2 years away. They simply wouldn't be showing this game this much if they were still that far away from release. They couldn't keep up with these kind of frequent showings of the game because that would mean we would have seen 90% of the game in the two years you still think the game will take to be finished, yet this is what people will expect going forward: at least an Active Time Report every 1-2 months and something bigger every 3-4 months. Around TGS the game was around 55-60% complete and it has been 3 months since then, so it's probably well beyond 60% by now, considering Tabata confirmed at TGS that they were already in mass content creation phase.
1) the streaming comment could just mean that they want to make a game without any loading whatsoever, but maybe they still have to have them for between going from outdoors to (bigger) indoor places and aren't sure if they want to or even need to change that if it seems too hard. Doesn't mean they are early into development, just that they have the same problem that most other open world/game-world-streaming games have. For example, indoors places are kinda hard to stream because you don't want to stream them pointlessly even when the character is just passing by a building (it's worthless to stream something the player can't see on the screen in front of him) when they already have to struggle with streaming some more or less vast environments and living, breathing world around the player character, but then again it might be techically impossible to have indoors areas stream very quickly WHEN the player does decide to suddenly check out some building after walking beside it. They are probably struggling with stuff like that, but that means very little in how far along they are. They can still proceed with making the indoors areas and whatever they have trouble streaming, a part of the team might just be trying to figure out if they can make the game stream the world in a way that there's no loading screen when entering & exiting buildings.
2) the length of day/night cycle is just about balancing the game and isn't some major hurdle that needs to be decided 5 years in advance. At the moment they are leaning towards in-game 24h taking ~1 hour IRL, but they could probably change some attributes in, like, 2 minutes and chance the length of day the day before the game goes gold if they feel like it. It has nothing to do with the game being in very early state, they just haven't completely nailed down wether they want one day to take 1 hour or if some other time felt better when it comes to the balance of the game. They could continue debating the length of day until the game is 99% complete. The biggest job was to create the day/night cycle and how it affects weather/lighting conditions & everything else in the world in the first place, adjusting its length isn't all that hard. It's just a matter of them wanting to make sure that the day isn't too long or too short when thinking about stuff like the eat & sleep gameplay feature. If the day is too long, then the sleeping stuff becomes somewhat pointless when it happens so rarely. If the day is too short, some of the longer battles might become annoying when all the debuffs start kicking in so early in the fight when Noctis hasn't slept for days or eaten anything and it might be really annoying if you have to run between hotel/shop & exploration/combat too frequently. So it's a game balance problem that they'll probably keep polishing & adjusting until the bitter end (game goes gold), not a "OH MY GOD THEY HAVE ABSOLUTELY NOTHING DONE OF THE GAME" problem.
3) They are adding a more varied move set for Noctis and also want to beef up magic VFX, so? Doesn't mean much in the larger scheme. We've already seen a lot of variety in how Noctis moves & attacks and they aren't done creating more options, doesn't mean they'll take 2 years to add a few more moves. And spell VFX could be worked on even when they are really close to finishing the game. It's just visual effects, not some fundamentally game-changing stuff that they need to nail years before the game is done.
4) it isn't all that huge of a task to program AI to use magic when they have already created the Gambit-like system and a lot of the magic to use for Noctis. Still, this is the kind of thing they'll tamper with until they are finished developing the game and is no kind of sign that they super early and that they'll still need to 2 years for the game's development.
5) the finished product will have better graphics and have voice acting in places that are still under work? SHOCKING.
I fully agree, some make it sound as if Square has nothing, but after thinking it trough they have quite a bunch of stuff.
They've shown plenty of footage so far, already confirmed there are more cities, summons and minigames. They're in mid-development, everything being planned out, blocked out, prototyped and now they have the gap with asset creation (there's a TON of assets that have to be created even beyond the things like textures, animations and other visual things, not to mention source control and the time it takes to compile a new build).
To go over the points.
1: It's not impossible to make everything seamless, but not easy either. It might need a fundamental change in their framework and something they might not have enough time for. They might run into cases were the framerate drops or pop-in is really noticeable and they might decide the easy solution is a loading screen, no big deal, certainly no sign that the game's in early development.
2: Exactly, the day/night, weather system is in place, as well as the fatigue system, otherwise Tabata wouldn't make detailed comments about that. It's just a matter of tweaking all of the values to get the system right, something they'll probably use the demo for as a way of feedback.
4: Don't know, it shouldn't be hard to make other characters use magic, but neither should it be hard to make other party members playable. Tabata said the Eidolon system came first, working on that now, and it would be in the demo version (March/April), magic would come later. (to be honest the TGS stage demo magic looked fine to me).
5: Did they say voice acting is still under works? They said they muted Cindy's voice for spoiler reasons. Maybe not 100% but from the quality of the cutscenes they have a large part of the voice recording and mocap, both in English and Japanese, recorded.
Think most cutscenes are done, and set in stone. The scenes from E3 2013 are final. As far as we know voice acting might've been wrapped up in both languages as I imagine Square doesn't want to lose too much money. (Jay Preston was cast in 2013 for Prompto)
Here's my guess what happened:
They probably focussed on cutscenes first when they "rebooted" it in 2011 while at the same time they made a prototype in Ebony, a temporary framework because others were busy with FFXIV. When FFXIV was finished (summer 2013) my guess is that they started on tools/Luminous 2.0 and the FFXV team continued cutscenes/scenario and slowly porting stuff over to the new engine. With this planned out and greenlit they could safely show FFXV at E3 and win some investors over.
Then we arrive at early-mid 2014 when their tooling, game systems and blockouts are getting together and they can start asset creation in full. Kitase mentioned in February 2014 that FFXV was
"far into development" and into full production.
Square can finally show something at TGS and decided to do a recruitment campaign to get new staff in to handle asset creation (,not making early development decisions

. Their progress is far along to handle a demo version and monthly broadcasts too.
All it comes down now is asset creation (i.e: level design, PBR materials, props, rigging, animations, AI behavior trees, normal maps, UI,...). Something they started a while ago, and which will increase in scale with new people coming in and getting familiar with the tools over the coming months.
My guess is they're at 65% complete right now, if not more and this won't take 2 more years.