1). If you're talking .38 special it's a revolver and has no magazine and it likely holds 5, maybe 6 rounds. If it's a pocket size .380 acp like I linked, it carries 6 in the mag and 1 in the chamber for a grand total of 7. That's a far cry from 17, and a .380 acp could easily need multiple shots to stop an attacker.
2). A glock 17 is a full size 4.5" glock chambered in 9mm. It has decent sights. It's not the same as the pocket size .380 acp or the .38 special. It's just not. Those guns are tiny and the sights aren't that great. Some guns like those don't even have sights to make them smaller and easier to draw. A laser isn't a must on those types of guns, but it sure could be helpful.
I'm not a gun expert, but the more you talk, the more people know you don't know what you're talking about.
Also, If you are willing to point the gun at the attacker you'd better be following it up rather quickly with a squeeze of the trigger. Don't flash a gun assuming that it will end the confrontation. If it's bad enough to draw it's bad enough to fire.