I can field a few.

1.  Check out the spell called "reveal" - I'm pretty sure that's what it's for.  Never tried it yet.

2.  Zooming way out on cloth map seems to work for me /shrug.

6.  I'd like to know this too because the way it unfolds now seemingly has no obvious pattern or logic - it seems completely random when it seems like there SHOULD be some logic to it

7.  Some techs will not always appear when you complete a research segment and get to pick your actual advancement.  Ex, you finish researching your next "block" of civics - the advanced farming or whatever that has a likelihood may or may not be available to select as the tech you get.

8.  This is always intersting to me.  You're researching things you don't know about, so why should you have a comlete tree available?  How do you know what you'll be researching 100 years from now?  Of course, from a gameplay persepective, and without some kind of randomized tech, you might as well have the tree, you're going to play thru the game and know it forever anyways.  It'd be slick to see a game have a more randomized tech system with randomized research times so that what should be unknown and discovered is actually somewhat unknown and discovered instead of planned out.  Sir.  We need a cure for cancer.  Ah, that'll take exactly 6 months in the medical tech line - chop chop!  Yeah.

 Can't answer but will comment on:

3. never noticed.  hmm...  kingdom summary has some good stuff in it and might have this...or it could be another mystery of Elemental

5. never tried...AIs in this game are so unstable I don't do much with diplo at this point, and it seems buggy or whacked in a lot of ways.  Most AIs die from other AIs, kill themselves with poor sov management, or are going to soon be a part of my empire, so trading with them is about pointless.  I have had all kinds of issues trying to set up simple treaties like nonaggression and peace - I get something they say they agree on, flail around clicking on stuff that seems to make the treaty actually happen, usually lose some gold because AIs think they're the shit even when I'm dominating the universe, and then the treaty doesn't take hold.  Sometimes I can repeat the exact same steps and it does hold.  I give up, really - they're all just gonna die instead - much simpler.

That link doesn't really answer #6 that I could see at a glance, and I really have no desire to read that entire thread to pick out the one piece of information I want.  :/

The problem with new tiles is that it seems woefully inconsistent.  You could have two newish cities nowhere near the tile limit with equal amounts of space around them at the same level of developoment/building and one city will have an endless supply of useable tiles available while the other will have few or none.  At least this is what I'm experiencing at times.

For ex, in a recent game I had one city I founded that had nothing around it for 3-4 game spaces and I could only ever place a few buildings around it.  Maybe 200 turns later I got the chance to place 1-2 more buildings.  All of my other cities grew and sprawled all over the place.  It never made much sense.  I thoght maybe the cities were too close together but I regularly see cities as close together and sprawling.  So...dunno.

"2.4 Why can't I build new city improvements even though I seem to have the appropriate resources?"

- There might be two reasons why the player cannot build the desired improvement:

1) The city does not match the appropriate level. Every city can reach up to 5 levels and most of the better improvements require a certain city level to be build. The level of the city can be seen in the Resources tab at the lower left section of the screen. The required city level for an improvement is listed next to the name of it, represented by a black castle tower icon. 

2) There are no free tiles left. Every city level provides a fixed amount of free tiles that can be used to build city improvements. The required amount of free tiles for any improvement are represented by a grey tower icon in the list for the improvement cost. The player can learn about the total amount of available free tiles for a city from the white resource indicator that is hovering over the city on the map or by clicking on the city detail screen (big circle at the lower mid section of the screen).

- Beware that forests, hills or any resource tile that is connected to the city will block free city tiles! In addition, the closer two cities are located to each other the less free tiles will be available to both of them. If you want to be able to raise cities to a high city level and build many improvements, you must provide for enough free space that surrounds them.

2.5 How can I get more free tiles / increase the level of a city?

- In order to increase the amount of free tiles for new improvements the player has two options:

1) Increasing the level of the city by building enough houses for the population to grow. The level bar at the lower left section of the screen shows the amount of people currently living in the city. The house icon in that bar is the population cap. Prestige, indicated by the goblet icon in theResources tab, indicates the rate in which new people stream to the city. In order to raise the population cap the player has to build more huts/houses (Kingdom) or shanties (Empire), which costs food.

2) Destroying built improvements to free up used city tiles. This option appears radical and counterproductive at first glance, but can be the only method in certain situations when there is no more room or food left to build new houses. Once the city reaches the next level and gains more free tiles, the razed improvements can be built again.

- Always contemplate the fact that it is a big effort room- and food-wise to raise a city to the maximum level and to be able to build a lot of city improvements there. Sometimes it makes more sense to specialize and prioritize, not every city has to reach high levels and has to house every single improvement to be of use. For example, it's perfectly valuable to build one city that incorporates a lot of resource tiles sacrificing building space but keeping them safe in return. Or to build mostly gildar related improvements in a city that has many gold mines in its vicinity, etc. Consider building military, economic, food cities if it appears sensible and there is not much room for city improvements."

Voila, Monsieur...

4. for Charisma, based for leadership, so not sure if they have this setup for D&D rules or close. so if there no purpose, why they put in the game in the first place?