1) The whole issue is greatly confused, but the upshot is that we have something like that which can be recovered at something like current costs, that we know about. Vastly more can be recovered at higher costs, and because the cost of ore is a tiny fraction of that of running a nuclear power plant (it's even a small part of the cost of the fuel, which takes a lot of processing), that isn't a huge issue. And once that runs out, in a thousand years, or so, we can move onto the Thorium; India is in fact doing so already. Still sounds better than gas and coal, in terms of security of supply.
2) Eh? Half the mines are closed, due to oversupply from weapons decommissioning. Note that the price, after rising for a while, is now going down again; that's because some of the mines are increasing production.
3) Eh? If you factor in the planning mess which can be required, sure. That's why EDF and so on are so interested in the existing (mostly closed) sites. GE says that their current plant takes two and a half years to build, from first concrete, while AREVA estimates 3 years. The AREVA one in Finland is due to overrun by a year or so, but that's largely because it's first-of-kind.
4) Again, simply not correct. Modern plants are FAR more efficient than plants from the 60s and 70s, even though there was a falloff in research. The plants of the 60s really were insanely expensive; the first nuclear plants in the UK and USSR were effectively government built, while the first one in the US was an aircraft carrier reactor whose design was contributed by the navy; they were worried that they were falling behind. The 4G plants planned for the next few decades are better again.
5) Plants are often uprated, though of course you can't expect huge gains. Of course, you're hardly likely going to want to upgrade your magic CHP thing in the kitchen every week until Putin turns the gas off, either.
6) Irrelevant if production is less efficient.
On nuclear plants bidding at 0p, that is because, unlike gas, but like hydro and most coal, they cannot simply be turned off and on when you feel like it; turning them on takes days or weeks. Even if they could, most of the cost is in staffing, construction, and putting money towards decommissioning, not in fuel.