Does putting apps and games in iphone makes it slow?

I have iPhone 4S does putting more apps and games in iphone makes it slow or lag or late responsive

If it is a large file & if the app/game is known to crash a lot.

Yes it does, due to occupying more gigabyte space. Try to keep it to a minimum.

No, it doesn't. Think of it as two boxes. In one box you have the iPhone os ( ios) and in the second box, all your apps and multimedia. Your apps can't interfere with the os at all unless your iPhone is jailbroken.
That's the reason ios is so much stable as compared to android.

Well, technically yes, but it depends. I believe that there's a certain range of free memory where your iphone is gonna start to be laggy. From my estimation and experience, just don't go lower than 1.5gb.

No it doesn't, but leaving them all open all the time in the background will of course.

Where is your HTC one x?