Temps on Laptop

I got a hp nc8230 for 30 dollars, pretty good steal in my oppinion.

the specs are:

intel pentium m 1.73ghz

ati mobility x600

2gb memory

Was wondering if the temps are ok, i get around 84celsius max for both remote temp and temp 1 on this laptop. I want to say ones for the graphics card and the others for the cpu, but unsure. Are these temps ok or are they too hot?

I have an Asus that gets up to 68 on heavy load, seems to me like 84 is way too hot, can you confirm that the built in fan is working?

Yes it does, i can fell it on the left side where the exhaust is.

My HP 2000 series GPU used to get up to 120 degrees (Measured by PC Wizard)when playing games. The Cpu would not be quite that hot, but pretty hot. Eventually, the entire motherboard failed.

Will a cooling mat help significantly for laptops? Also i get memory leaks during games on the laptop, after i quit out my computer will be losing around 500mb rnadomly somewhere. Can excess heat cause memory leaks?

I opened up the laptop and reseated the heatsinks that were on the cpu and gpu and now my max temps never go above 60. Its seems that the person before me had opened it before and didn't seat the heatsinks right or something, plus they used crappy pads rather than thermal paste for it.

I was wondering though is there anyway to change out the cpu in the laptop, it almost seems like you can take it out like a desktop processor, but am unsure of it. Is there a way to change them out at all?

I've looked some up and found some pentium m 780 that are at 2.26ghz instead of 1.73ghz. Also would like to overclock it if possible to same me time and effort because i heard these mobile processors are pretty decent at overclocking. The only issue is finding a compatible pll for the processor.