Hello Iko113
Honestly I would start over..
I recommend a non-journaling file system like ext2 file system for a USB stick
and ext4 for a regular old HDD
create
sdc1 (DOS/UEFI) for your boot files
sdc2 (ext2) for you home, opt and tce directory structure
--set=root will probably need to be the first partition so that grub can find your /boot/ "linux files"
blkid -s UUID /dev/sdc1
You're showing errors with unsupported file systems from a booted tinycore which is unrelated to grub.
You can verify which file systems gparted current;y has support for by checking gparted menu; Gparted > View > File System Support
If a file system is not supported then load the appropriate driver, eg;
tce-load -i e2fsprogs
then close and reopen gparted
Also this has been said many times already (not that this is an issue yet, but will be once you've provided grub with the correct path to your linux files...) CDE is for a read only Compact Disk. After copying the contents of a cde directory to a USB stick or HDD, you must change the directory name from cde to tce and remove the cde entry from your boot config file.
An example of grub.cfg from my currently installed USB stick
insmod part_msdos
insmod fat
insmod ext2
loadfont unicode
insmod efi_gop
insmod efi_uga
insmod font
insmod gfxterm
set gfxmode=auto
set gfxterm_font=unicode
set gfxpayload=keep
terminal_output gfxterm
#Timeout for menu
set default=0
set timeout=5
menuentry "*** TC-9-x86 (Nvidia on USB)" {
search --no-floppy --fs-uuid --set=root B854-8FE0
linux /boot/vmlinuz-41410 vmalloc=384MB tz=GMT noswap loglevel=3 waitusb=5:UUID="b313c2c4-fedf-4c44-bf42-6a6fca54b311" tce=UUID="b313c2c4-fedf-4c44-bf42-6a6fca54b311"/tc9-x86 opt=UUID="b313c2c4-fedf-4c44-bf42-6a6fca54b311" home=UUID="b313c2c4-fedf-4c44-bf42-6a6fca54b311" lst=onboot_x86_Nvidia.lst mydata=mydata_tc9x86.Nvidia
initrd /boot/rootfs-90.gz /boot/modules-41410.gz
}
menuentry "*** TC-9-Corepure64 (Xorg on USB)" {
search --no-floppy --fs-uuid --set=root B854-8FE0
linux /boot/vmlinuz64-41410 noswap tz=GMT loglevel=3 waitusb=5:UUID="b313c2c4-fedf-4c44-bf42-6a6fca54b311" tce=UUID="b313c2c4-fedf-4c44-bf42-6a6fca54b311"/tc9-x86_64 opt=UUID="b313c2c4-fedf-4c44-bf42-6a6fca54b311" home=UUID="b313c2c4-fedf-4c44-bf42-6a6fca54b311" lst=onboot_CorePure64.lst
initrd /boot/rootfs64-90.gz /boot/modules64-41410.gz
}
menuentry "System restart" {
echo "System rebooting..."
reboot
}
When you have multiple drives and partitions it's important to specify the correct path to the linux files you wish to use.
Remember this is only a partial example from a USB install I use on a 64bit UEFI PC in compatibility mode, so YMMV
I suggest set root and partition layout is holding back progress here...