I recently bought this ram that is cl4
http://www.newegg.com/Product/Product.aspx?Item=N82E16820231154

the downside is they seem to get to hot for my laptop to handle
i plan to order a laptop cooler when i got enough money
until then does it matter if i use my old ram and dual channel it with my new ram

Also why is the ram timings like this?

If you are referring to there being tables for multiple speeds, that's normal. It is there so that a computer that does not support the full speed will know what timings to use.

As for it not showing the advertised timings in the table there, that is also normal. Not all motherboards will work with the lower timings, so they set the defaults to be more normal. Unfortunately, with ram for laptop computers this may mean it could be impossible to even use the advertised timings, as many BIOS on laptops don't let you configure those things.

You should be able to use your old ram with your new ram just fine, provided you have the needed number of slots. The computer will run both at the same speed, which will be what the slower of the two modules supports (but this may be beneficial, as far as the level of heat generated in the laptop). Unless they are the same memory capacity, you cannot run them in "dual channel" mode to get the associated performance boost (this doesn't mean you can't use them together).

Anyone wanna recommend me a laptop cooler for 15.4"

They all work well.

is 50C normal for a laptop with a core2duo?

50 celcius doing what? Idling?
Even then, I am not too familiar with laptops and how hot they run, but I know CPUs don't generally like to run in past 60C.

I am currently only on staredit and its going 50-52C

If you could find out how high your temperature rises when you stres your CPU (using prime95 or something similar) that could help determine if that is a good temperature or not.