Second question first, as I mull over the first question:
Ratfolk would be a definite player choice, I'd think. The Ysoki rat-men.
The lizardfolk seem like they're just asking to be a PC race. It isn't exactly clear if they're "standard" lizardfolk or some other group, so you could have them be variant Nagaji (for which there are existing PC race rules), create your own race with the race builder, or use the 8 RP version of the lizardfolk from p.226 of the Advanced Race Guide, which would start out as a 1st level character.
I'd also be tempted to use the Shobhads myself, and create a 1st level version of their race with the race builder. A version of the Kasatha would be the template I'd use; a 20 point build is already quite beyond most standard races, and a Large one would add 7 more points. I'd probably make some adjustments to temper that down somewhat, and you'd want to follow the ARG's guidelines for adjusting encounters for groups with high point builds if characters play as one.
Elves are mentioned in Distant Worlds as not being entirely unknown, so I'd probably allow them. Maybe a clan or two that had long ago emigrated to Akiton from Castrovel.
If you're feeling really creative, maybe create a player version of the Contemplatives.
As for where to begin, I guess it depends on the sort of campaign you're running. For me, I'd probably have them start as members of some sort of mixed/integrated racial nomadic tribe. That way, you can gradually introduce them to the alien-ness of the planet in an organic way- the tribe is threatened, perhaps nearly wiped out by some threat. The characters manage to survive, but now have to trek their way across a hostile world, gradually making their way to some of the more "civilized" areas. I'd probably get them to the Hivemarket first, saving some of the the cities for later adventures and again- to gradually indoctrinate them into this alien world. Desert nomads, while they are probably familiar with various legends and lore of the world, wouldn't have had any reason to visit the cities and settlements until necessity forced it.
It could make for a fun Gamma Worldish/Post-Apocalyptic/John Carter of Mars style campaign, that's for sure.
Also, see this fledgling thread for more on what some other people's thoughts are on Akiton. It's not nearly as large or developed as the Everyday Life on Verces thread yet, but with some help it might get there.
And before I forget, there's N'wah's Akiton Runelords thread, outlining a Rise of the Runelords campaign re-imagined on Akiton.