You can get 100 ohm 0402 sized Resistors at pretty much any online parts place. DigiKey, Mouse, etc, etc. If you can't find them at any of those places then you aren't looking them up right.
The 100R should be 100ohm, use a DMM and check.
R42 and C38 are missing in the pic, 100 ohm and 470nF, and those are on the Output of the Hall Sensor. Ground for the Hall is pin 3 and looks fine from what I can see in the image.