would it be fine to use a 4 year old computer case keeping the cd drive to build a gaming computer in
It is fine.... but I would advise against it. Newer cases have better cooling which you need for a gaming computer.
That all depends on the case...I've got one from about 10 years ago that has better cooling than most modern cases. Also, if you have a dremel tool, any case can have great cooling.
I generally don't recommend you use an old case for a gaming PC unless you intend to modify it heavily. Newer cases use the updated ATX form factor, will cool better, and are better able to fit the parts.
Agreed, it depends on the case. If it's only got room for one small fan then it's a bad idea unless you hack it up and add more.
