Towards the end of the samurai as a caste, it was all but hereditary. However, that wasn't always true in earlier eras there was more social fluidity. It is possible that someone could perform some exemplary deed and be "elevated" into the samurai caste. Elevated is in quotes as there could considerable expenses to maintain that rank. By Nobunaga's time, the deed would need to be truly exemplary and such a request would need to go through and be approved by the shogunate bureaucracy.
Completely pointless. Unless you are sitting on your own private gas station or have an oil rig in your back yard where you can distill your own diesel, any ICE vehicle is going to be dead weight after the first week of an EMP attack.
Be Ukrainian fighting age male. Russon-Ukrainian starts. Escape from Ukraine. Join the French Foreign Legion for a no questions asked French citizenship. Be sent to die in the Russon-Ukrainia war anyways.
I am pretty sure that SpeedTree just takes your art assets and uses them to display trees in the best performance and most immersive way possible. It probably has some default art included, but you would normally still need to supply the art (textures, bump maps, etc.). Compare Skyrim LE, Skyrim SE and then say a really well modded version of the game using the latest mods. You'll see an evolution in progress from barely passable to stuff that is truly incredible.
However, this all depends on their artists being any good.