The Q6600 is about one of the warmest processors Intel ever made. It's an older Core 2 Quad processor made using the older, less efficient 62 nanometer CPU process. Newer 45 or even 32 NM processes use much less electricity and are much more efficient, so they generate a huge amount less heat. 160f at idle is a bit higher even than is ideal for that one, but generally that particular CPU had a normal operating temperature of around 145 under load. So 160f on the processor is not a happy computer. Should be safe with the large fan on it until your temperature drops though. Of course, the bios for that motherboard might also be off on the temperature values. they sometimes are, but better to play it safe.
This is the internal layout of your case. Its not the same exact motherboard, but same family of cases.
http://support.gateway.com/s/CASES/GERSHWIN/3507057Riv.shtml
Basically you have what look like 2 92MM case fans and a modified shrouded CPU cooler. The CPU cooler was probably intended to draw cold air from the side of the case, but I've never really liked those duct inlet styles because they end up actually preventing some of the primary fan air from reaching the processor, especially if that side of the case is up against a wall of any sort. It's not an ideal case layout coolingwise, but since the motherboard is probably proprietary, you're probably stuck with that case until you decide to upgrade the motherboard.
The video card is probably a bit warm at 169, but they can handle higher temperatures. for the 9800 gt 174f is about the highest safe temperature it will take and even that would be a bit warmer than I would want to run it.
If you do alot of gaming, you may want to consider upgrading to a cooler running case and a faster CPU/motherboard combo. Will save you money on electricity if nothing else
edit: Also, though your chipset "should" support going with a newer core 2 socket 775 processor, assume it doesn't. Gateway corporate went bankrupt about the time that PC was released, and they got bought by MPC, which also went bankrupt. Gateway consumor survived, but they don't really do much bios updating to the older computers at all.
Edited, Sep 12th 2010 3:58pm by Kaolian