I don't think you can change it on that board. that's why we build our own computers. We have more options. If you can't find anything called timings that is not related to the clock, you are not able to decrease the timings.
Still, it's 8gig running at 1600 mhz and CasL 11 which is still better than your last setup. And no, buying RAM with higher latency is not gonna be any cheaper. RAM have a certain price. increasing the CasL or lowering the mhz (which is both worse options) are not gonna make a 2x4 kit any cheaper if it's decent quality RAM.
So if you don't see any timings options (which i don't think you do, giving it's Medion) you are not able to decrease the timings. Your motherboard wont allow it. it's not gonna make huge difference anyway though.
It is. I am not exactly sure why, but programs like CPU-ID and many more show only half while it's still running it full speed. You can goolge "ram speed half" and check it out for your self.
btw. You have to set your timings manually in the bios. Motherboards tent to automatically set RAM speeds or timings lower to be safe. It does that to be sure the computer will post with the RAM the user want's to install. Because you can always change it yourself in the bios. If the computer didn't post at all, you would be screwed. So that's why motherboards that are not installed in a computer by a manufacturer does that.