u/Equal_Cockroach_1032

Hi everyone! This is my flight controller design. Please help me review this design. The project capabilities are:

STM32F405RGT6 + ICM-42688P + LIS2MDLTR + BMP280
Have at least 1 of each communication protocol (e.g. CAN, I2C, SPI, UART) available
Output 12V 1A and 5V 1A from buck converter
Output 3V 600mA from LDO from 5V input
Capable of powered on by USB or Battery
Can communicate with SD CARD (1 bit SPI mode)

What have I learn and applied so far:

Some crystal oscillator layout such as no routing under crystal oscillator
Follow the datasheet recommended layout for buck converter and other components
Make the USB traces to have most similar impedance (I read that it's not required for USB 2.0 because it's considered low speed)
Make sure the decoupling capacitors are close as possible to the components
Separate the logic and power

The things I'm not sure of:

Is it okay to place the power components under the SD card slot? Will the noise and heat affect the SD card communication?
Is it acceptable to put ground vias under the icm-42688p? Will the noise affect the reading?
Is it okay if the feedback voltage of the buck converter is from the voltage after decoupling capacitor?
Should I place stitching vias on this board?

As for reverse polarity protection, I'll try to put a diode somewhere around the battery pad on the board later on.

Hopefully you guys can help me to make it better. I'll accept any advices you guys give. Thank you very much everyone!