Yes, to the first. No to the second. Subject to the below.
OPEN, READ, DISPLAY, repeat until end, CLOSE. With FILE-STATUSes of course.
The only neat alternative I can think of quickly is to put your existing output from the Delta Cobol program to a dataset and then run another little step to "copy" the files, concatenated together, to on SYSOUT file. A little SORT step would do it well.