My apologies for the angry rant introduction - that was my initial response. I hope that you can accept me for a regular round-earther, not an asshat.
Anyway, on to my main point - The Ice Wall.
It is, as i see it, impossible for this wall of ice to remain in a frozen state. Where does the lack of heat come from (Hah, I know that sentence is stupid, but you get my drift). In a world that is lit by a spotlight strong enough to light entire continents to the point of > 40 degress celcius, how does it remain frozen?
I know that in the round earth scheme of things, exactly the same thing happens - a giant body of ice remains frozen (despite that it is melting...like what happens naturally) at the north and south poles. However, the atmosphere plays a big part in this. Number 1, it's pretty much overcast all the time. In a flat earth theory, clouds, and indeed anything, would have a great amount of trouble in staying at high altitudes right above the edge. Assuming the earth is flat, and is accelerating 'upwards', then this would force all matter to 'spread out' because the air beneath the air on top cannot support the weight of the air on top. You can demostrate this easily at home. Thanks to the wonderful forces of surface tension, you can just use water. Get a plate (or an even flatter object, which would be better) and try and put as much water on it without it pouring off the sides (because, like what has been said before, you'll get wet in the laps...what an odd phrase...anyway - ). Here, the earth's gravitational pull will account for the flat earth's 'falling upwards'. Now, here's the fun bit. Pour more water on the plate, in fact, pour a greater amount on each second, in accordance with 9.8 ms/s. You will notice that the water pours off. The adding of water is effectively 'the air on top' while the water you put on there is 'the air on the bottom'. The both, 'bottom air' first, begin to run off the disc.
Back to the atmosphere...
As demonstrated, clouds, and indeed probably a goodly amount of air, would be falling off the disc (and there's a little bit of the answer to "whats on the bottom?" This, therefore , removes most of the atmosphere covering the Ice Wall - add leaves it open to not only immense radiation from the sun, but also anything else coming from surrounding heavenly bodies.
Since the Flat Earth theory extends out past the earth, we can therefore assume that much of the rest of the surrounding universe (because of Quantum, other universes potentially exist, and therefore may have different mechanics) is flat as well. This also eliminates the possibilty of a Heliosphere and similar spherical bodies enveloping our solar system. As most of you well educated people should know - The Heliosphere is the first, and an important line of defense against the constant bombarding of extra-solar radiation. Without this, a flat earth would take a significant pounding - probably to the extent to where earth - flat or round - coulnd not have life existing on it. It could, resource-wise, support life - but the radation from extra-solar bodies (hell, even our own sun) would snuff out life as it tried to evolve.
Anyway, this radiation would contribute to the melting of of the Ice Wall.
Another thing - climate shifts. If it
were possible to have an Ice Wall so thick that it was able to hold back the oceans, then it would gradually melt due to global warming.
What's that, you say? Global cooling? Ah! Possibly a very valid point indeed! However, Global warming and cooling - two opposing mediums. To prevent the earth from freezing over, you need global warming. To prevent the "Ice Wall" from melting you need global cooling. This suggests that there is a balance between the two. However, as you can notice in everyday life - nature cannot remain balanced -
change is inevitable.
We would, over the process of many aeons, shift from bloody cold to bloody hot. The 'bloody hot' would melt the Ice Wall. There is no challenging this - ICE MELTS - as it is doing so now at our earth's polar extremeties.
Another point - flat earth claims the ring of ice around it's circumferance. This is impossible. Here is a diagram of the only possible way I can see the earth as being flat - (excuse the crudeness - I'm not that great with drawing on the computer). Not only would the earth being pushed upwards force the Ice outwards from the earth - eventually falling off the edge, but friction would break it apart as well. I'll get to that soon.
This "thicker at the middle" disc is the only way I can conceive that a flat earth is possible. You mention that the flat earth can tilt (and assuming it never falls on it's side, due to the fact the upwards force would eventually do this to it). If it tilts, and there is force pushing it, this would cause it to rotate - eventually on an axis. As you might have thought already, this will eventually form into a ball. The centrifugal/pedal (whichever you want to go with) will do this. But for now, lets say its at the state where is is going to be a disc for a rather long time. The previously mentioned forces will make this disk expand, gradually cracking it, and the additional weight of the ground and air pushing out sideways will help this.
I mentioned friction before. As you will all doubt know, ice is Slippery When Wet. There is a great amount of water pushing against this ice, and this would cause at least the sides and the ground underneath the ice to become very slippery for a good few hundred kilometres undernearth. Remember that this flat earth is still spinning. The ice over the slippery (my apologies for the use of the word 'slippery'. I need to think of a better term) land should have no trouble in keeping up with the spinning earth - centrifugal force will keep it moving at the same pace (as well as flying right off it..). However, the ice that is not in direct contact with the water will be trying to move at a different pace to the 'slippery' ice - because they interact with different physical properties with the spinning disc. This would gradually crack the Ice Wall also...and then water will invade futher, and so on and so forth. The warmth I mentioned before should help prevent ice reforming.
As a conlcuding point, for the Ice Wall, that is, I must add how the idea that the Ice Wall is completely transparent is completely ludicrous. For aeons, we have collected junk from outerspace - and this Ice Wall would be a prime target for space debris. Not only this, but junk from our own planet would be formed in the ice as well - It fact, it would be about as see-through as your own eyelids - possible, but only up VERY close and with a lot of light on one side.
In final conclusion - I suggest you find a new logo for the site, because not only does the theory contradict it'self, but so does your logo. As soon as I looked at it, I immediately saw this:
And so, in summation - The Ice Wall, and very much therefor, the Flat Earth is impossible - In pretty much any way you look at it.