Answer to Question 1
(a) If inter-generational, or economic growth considerations are taken into account, then a country may end up specializing in a good that has no or few growth linkages with the rest of the economy (e.g., an enclave sector).
(b) If some of the residents of a country have tastes biased toward their exportable, then they may suffer due to the trade-affected increase in the market price of the exportable good.
Answer to Question 2
(Eruble/franc, t - Eruble/franc, t-1)/Eruble/franc, t-1 = 2 - 0.02 = 1.98
So there will be a 198 depreciation of the ruble against the franc or, conversely, a 198 appreciation of the franc against the ruble.