Yes. Unless it melts.
My charger gets really hot after 30 to 45 minutes of charging, is this normal?
how hot exactly? too hold to touch?
It's not too hot, just hotter then my usual PC chargers. And does anyone know is it better to use the AC cord or use wall adapter?
Just don't use it to warm up your crotch while you're sleeping during winter.
Not a good idea.
It depends on how much you're using the computer. The more taxing your use, the more power it needs, and then the charger works harder to provide it, and gets hotter.
If you're just checking your email, the charger will probably be just a tad warm, but in my experience if you're rendering movies or something of that sort it will definitely get pretty toasty.