sorry got the two progs mixed up:
Fdsave (to image) and fdload (to disk) are like you said. FDSAVE can't handle protected sectors, crc errors etc (only some minor things). So it stands to reason that FDload can't write protected sectors, crc errors TO disk. I have created disks from diskimages before with FDLOAD so I know it works in general. C-qser shouldn't pose a problem since it can also be 'installed' in a dos 2 directory iirc.
Possible problems fdload:
1. FDload doesn't perform an 'auto-format'. So lets say you try to put a diskimage from a singlesided disk on a doublesided (unformatted) disk: that might pose a problem.
2. minor corruption in the diskimage: minor enough to be able to execute the diskimage but big enough for fdload

3. diskimage contains 'odd information' as Snout puts it
Possible solution for problem 2:
- format a diskette
- in dos 2 enter the virtual disk with following commands:
ep <drivename>:<diskimage> /d
cp <drivename>:@0
- copy all files from virtual disk to regular disk
Possible solution for problem 3:
- don't use fdload but use dcopy or HDDemu instead