Dell Laptop overheats and shuts down

Hi I'm wondering if its normal for my laptop to be overheating and shut down? These are my specs:

Dell Inspiron 15R
Intel Core i7-2670QM Processor 
8 GB Memory
1 TB Hard Drive
1 GB NVIDIA GeForce GT 525M

I play this game called Team Fortress 2 and have installed configurations to make the game look pretty awful for performance reasons. However, my laptop still overheats. My fan is working for sure because I can hear it and its blowing a lot of hot air out from the vent. Also I give my laptop plenty of ventilation (I have a hardwood table and I even put sticky note stacks under my laptop so there would be room for air). I know it only happens with games because every other time I'm on my laptop when I'm not playing a graphically intense game, it's fine.

I talked to someone at Dell before and I updated my BIOS and video card drivers but it still didn't solve the problem.

So from here I have a couple of questions:

1) Is it normal for my laptop to be overheating with these specs? I felt that the video card and processor would be strong enough that heating wouldn't be an issue at all especially considering I have my graphics super low. Then again idk much when it comes to hardware. 

2) If it is a heating problem, the only last possible thing that could be causing the overheating, I think, is dust but even there I'm a little skeptical because I bought this laptop like 2 months ago and am surprised it would already have a dust issue. Do you think it's still possible?

3) I might go buy some compressed air but I am also curious to see what's happening inside my laptop. Maybe there's something blocking ventilation? However, I do still have a warranty on my laptop and I don't want to void it. Will my warranty get voided if I open my laptop?  

4) Has my laptop suffered permanent damage because it has been crashing from overheating? Am I frying my graphics card? I just want to know so I can be careful more.

5) Is there any other reasons that could be causing this overheating problem? I guess it sometimes gets hot in my room because I live in Cali but we turn on the A/C and my room feels ridiculously cold. Even then it sometimes overheats.

Thanks for all the help you guys can give!