OK.

chance that NOLOCK will be ignored is other thing than NOLOCK to be harmful. so I can keep this NOLOCK anyway, what do I have to lose here?

How do you suggest to update rows with a mode of "I don't care if few rows where not updated" - something like "readpast" .

do you suggest to use temporary table for that that will have the data by using select with (READPAST, ROWLOCK, UPDLOCK) and than update it?