Wow, you're very thorough! Thank you for asking X'D
**SPOILERS ALERT**
So yes, while the merchants often advertise their rice to be from spring village, it's not necessarily true. It could've been from other places, but because Spring Village's popularity is high, they borrowed the name just so they can sell better 😂
Another answer (a darker one): since the antagonist had hypnotized the Autumn villagers early, the merchants would've obtained rice somewhere else and thought they had obtained it from the Spring Village. Because it's the "routine" they had in their memories.
As for the Dryads, yes they're a very reclusive tribe and history hasn't been kind to them. Now, the survivors are either asleep now in their own trees in the forest or just live in hiding.
As for Rama... Before I answer this, have you played Winged Ones? X'D I'll try to give a spoilerless answer: Yes, out of the other bachelors, he needed Tamara the most.