The problem should not relate to symbol link, go the the actual directory and try opening the file, issue remain.
if it's about access right, that doesn't explain why other plain text editor can open and save as normal after granted the root right when prompt.
And TC behave strange in those folder too, can't mount as RW, saying
Note: other application can access those file at the same time, so it's not true about "resource busy"
P.S.
personally, I don't think it is necessary to mark out symbol link by default, that make the layout a little chaos in some case...
and finally, a feature request:
would you consider making the highlighted toolbar always show at top? it's annoying sometime when scroll up and down in folder with many file, like /sdcard/
back & forward are also nice to have
Image:
http://i.imgur.com/Gk3DQ.png