1. The Terrakin are supposed to be humanity, though they don't entirely look the part.
2. There's an SR1 portrait mod
on the Workshop, including a pretty good human portrait. If this is not an option due to your having a non-Steam version of the game, I can only point you in the direction of the Alternate Balance Expansion Mod - it contains a modified form of Vincent's mod. (It also contains a bunch of other stuff, so ABEM is not necessarily
a good choice for a new player. Way much more to learn.)
If you're interested in ABEM, you can get ABEM 0.3.0 from ModDB
, or the Steam Workshop, where you can choose between 0.3.0
and the 0.4.0 beta