Every time I copy files from my home (ext4) partition to a Windows (ntfs) partition in Double Commander a dialogue pops up saying "can not set attributes for... can not set date/time for..." and asking to choose between Skip, Skip All, Ignore All and Abort. I am to press "Ignore All" manually all the time. Can I just configure it to ignore this problem automatically?
Yes, you can configure to ignore this automatically.
Copy a file with F5 key or "Copy F5" at the bottom of Double Commander. A dialogue will come up, choose "Options". At "When cannot set property" drop down list select "Ignore errors". Then click "Save these options as default".