In Fedora 10 and lower you could set the default mount options by using the gconf editor and editing \system\storage\default_options\ntfs
In Fedora 11 the new DeviceKit service doesn't interact with the gconf anymore so these options are completely useless.
What did you try in fstab? At home my external HDDs are formatted FAT32 and I prefer to have the "shortname=mixed" and "sync" options on them, so I have my fstab looking like this:
UUID=4929-C14C /media/MIDNIGHT vfat noauto,user,rw,nosuid,nodev,uid=500,gid=500,shortname=mixed,dmask=0077,utf8=1,flush,sync
I don't notice any side effects, except that my "MIDNIGHT" volume has 2 icons in the Places menu (one looks like a mounted volume and it opens the /media/MIDNIGHT folder, the other looks like an unmounted volume and it gives an error if I double-click it). I can right-click the mounted volume icon and unmount it that way and then use the other icon to remount it. Besides that, if I unplug the drive both icons disappear, and plug it back in and both icons come back.
Also on XFCE, this method only results in a single icon per volume, not the 2 icons that I get in gnome - so in XFCE, no adverse side effects at all.