Q1 - Yes, but its possible (well, likely), that you'll never make the most of the increassed speed. If however, you've been limited to 1Mbps broadband until now because of distance from the exchange, you'll still see a nice speed increase even using wifi. The better your wifi, both type and signal strength, the faster it will go. N is better than G, and if you can find a setup that support 5Ghz as well as 2.4Ghz then potentially you could get upto 300Mbps, which is far in excess of the Fibre speed. That said, wifi is prone to all sorts of interference drop outs etc, that while not harming a normal surfing experience, may make speed tests look a bit slow.
Q2 - Its the best way of getting a fast, stable and reliable connection. Wifi is pretty good most of the time, but in my experience it still doesn't match the consistent speed of a cable run.
As the BT engineer will fit the same equipment in the same place regardless of 1 or 2 above, why not have him fit it, and see how it goes.... you can always run a CAT5e cable afterwards.
