No. No-one makes larger panels, and the CPUs can't just be "swapped" for a better one
The most you can do is locate IPS panels for beter viewing angles. Nintendo were very inconsistent with whether units had IPS or TN panels and many come with one and one
No such luck I'm afraid. the 3DS only outputs the resolution for the screen it's designed for. You'd have to come up with your own scaler PCB to blow it up to fit the higher res, if a screen like that even existed