Well I did a little searching around for a dedicated screen capture program that meets my needs and one that works really well is called SnapShot. It's free and so far as I've tested it out, it's really good.
Basically all i have to do is press the hotkey "R" and i can begin to drag mouse click to any size box i want to capture. Once I let go of the mouse click, it automatically saves the captured image into a file (you choose where the saved files should go), and that's it. There's no outline box or size dimensions that get captured. It also allows me to keep the program minimized after a screen capture so that I can take multiple/consecutive screencaps. It plays a simple "camera click" sound effect to indicate you took a snap. You can actually choose your own wav file and swap it to have a custom sound effect each time u take a screen cap.
The only downside is while doing multiple captures, i still have to press hotkey "R" each time before taking the snap. PSP just lets you keep on taking captures over and over without any hotkeys. But what I like about it is that it auto saves the file immediately so it saves me from having to save all 200 screencaps at the end.
But most of all, there's no issue with laggy frame borders or size dimensions in the middle (I used MPC HC and worked fine there).
I guess this will be my workaround to resolve the screen cap issue with Corel PSP. Of course, I'll still use PSP to do any post editing of the saved screen caps i took from SnapShot.
Hope this helps anyone who has gone through the same "outline/frame box and size dimensions showing up in screen caps" issue.