I'll speak to point 5.
This is not the case for Civ5, and I consider that to be a benefit. It encourages varying gameplay styles.
Small empires are not at an inherent disadvantage to larger empires. In some cases (as in the case of cultural victory), you are rewarded for maintaining a smaller empire. In other cases, you can still maintain some parity with a larger empire (largely due to the global happiness mechanic, separation of research from commerce, and city-states). And in some cases, you are at a disadvantage, such as military conquest.
This makes gameplay less one dimensional as it pertains to victory conditions. It does force you to make difficult choices (e.g. should I expand to that 4th/5th city for a military/tech advantage and effectively eliminate cultural victory as an option). It does attach more permanence to your decisions than the decisions made in Civ4. It means the cost of your decisions won't be relegated to solely opportunity cost. But I consider these difficult decisions the basis of a good strategy game. I consider the long-term ramifications of your decisions an improvement. The flexibility you miss, I am happy to see gone. It rewards well-thought out plans and foresight. And to me that is what a strategy game is about.
The game certainly needs massaging. But ultimately I feel once more work is put into balancing the game, the decisions are going to be harder to make in Civ5 than they are in Civ4. The path to victory will be less evident than it was in Civ4. It's not there yet, but I look forward to it. The game design is certainly better set up for it than Civ4 ever was.
This is a myth and that marketing bla bla from reviews.
I tried 3 times to play Civ V, while in 3 games I intentionally used some predefined strategies
1) Game 1 - played as Civ IV
Balanced expansion, production, military. As a result I have constant problems with happiness and money - I was stupid and kind role-play the game, building cities next to each other (not those crazy city states all over the map), trying diplomacy, dealing peacefully with city states etc. The game become hell boring as to fight with unhappiness I had to build some happiness buildings, when build buildings, maintenance costs was killing me, so I started to look more for luxury resources and to build more cities near. More cities = even bigger problems with happiness. When I once annexed one city through conquest - I had to deal with all problems it caused for a long time and I actually regret I just didn't raze it (all later I did).
I didn't like this game but I learned that strategies from Civ III or Civ IV won't work here.
2) Game 2 - trying those "small empires"
This time I played as a "small modern country". I build just 3 cities, many wonders, very small but efficient army to defend myself from aggressive neighbours. I also allied with 2 city states to get some bonuses. My people were happy, I had money, golden ages, I was unlocking many social policies, thanks to great culture boost and then... I
noticed, my neighbour India (who surprisingly was quite aggressive) already managed to conquer the whole continent and was running around with infantry and tanks, while I just developed cannons!
And this is the whole myth - "small empires" even with all educational buildings, free techs from great scientists, research agreements, won't ever pace big ones in tech race, not talking about military.
Surprisingly India spared me, with no reason, but I knew the game should be lost if AI would be a little bit more smart, so I didn't even waited to see if I win this cultural victory and gave up a game. So cultural victory won't work here...
3) Game 3 - constant conquest
So now, I tried strategy of constant conquest. I had just 2 own cities (actually... 3 because once I clicked wrong button) - all the others were puppets. Surprisingly it started with a coalition of Greece and Rome which declared war on me, with Greece even able to conquer my capital for a 1 turn, while I have forces elsewhere (I just mention that, to show that in fact I did few severe mistakes which had no influence on anything). I build few archers and horsemen and quickly conquered Rome, then Greece, then few surrounding city states and move one and on. In three cities I built only military units, didn't waste time for wonders, or buildings. Besides I built just one worker. Cities fell one by one, no diplomacy, just constant war. Unhappiness 8? Who cares - people will just have less sex. Unhappiness 18? Also no problem, I had more units anyway and were better. Money? No problem, with every captured and vassalised city, I got new cash so I could ran with a deficit for a long time. As an addition I turned great generals into golden eras, and have few flying squads to clear constantly spawning barbarians. Finally I had war with everyone beside I city states, but who cares - city states won't move outside of their borders and Civs are too stupid to take any war initiative.
I could easily win, but due to stupid bug, I couldn't declare two last wars (
http://forums.civfanatics.com/showthread.php?t=389002)
So... sorry.
Does anybody see any depth or strategy in my last game?
My "empire" was in fact a union of hardly connected city states, which looked stupid on a continent map. Beside, having 2 own cities, 1 conquered and plenty of vassals is plain stupid - it wouldn't ever work in real life, as all of them would revolt at once.
I also didn't have to bother about buildings - they built what they liked, how they liked and where they liked - I just moved my armies on the map.
If this is a "grand strategy" game which "forces me to me make to difficult choices", to consider opportunities and opportunity costs... sorry but I played probably a different game.
I would even risk to say: Civ 1 was more demanding, because of governments falls, corruption, maintenance costs (how they could forget about distance to palace drawbacks), caravan handling and especially military tactics of sudden death (I remember I had to think hard, how to stop enemy tanks, while I had just cannons and musketeers).
I was very open about Civ V, gave this game 3 tries, but now I gave up completely.
P.S. I played my games on Prince and King difficulty levels (don't remember which one when)