10.51 Can I have "openq @" in my sysstart file, or do I need to have a line for each ldev (like I currently do, which amounts to 40 lines and now I need to add more printers)?

OPENQ is a valid SYSSTART command and is usually recommended for systart in the form OPENQ LP.

OPENQ @ is not substitute for an OPENQ of each individual device class. OPENQ @ and SHUTQ @ only manipulate a flag that MPE uses to determine if spooling to ANY (not EVERY, but ANY) queue is enabled and disabled. Whereas an OPENQ devicename will enable/disable spooling to an entire device class. (With that said, most printers, by default, are initially spooled based on their respective sysgen/nmmgr configuration.)