Thanks for your interest! I am in no way connected to OLPC organization (other than the fact that I own a little green guy
so anything I say is unofficial (and quite potentially wrong even!)
1) "Efficiency" is a hard metric to measure. What are we optimizing for? The OLPC was opimized for low power, low cost, 3rd world country environment with little to no reliable power source. Are these the same or similar conditions for your rural environment? Not to mention their distribution model indenting for the destination governments and school systems to subsidize the program.
2) Those seem to be youtube videos, for which the XO is capable of playing most, in general. I haven't specifically tried to load those pages in my XO yet.
3) The wiki
may be able to point you to some resources.