The surface you see inside the camera when the shutter is open is actually not the sensor. It's the low-pass & piezoelectric filter in front of the sensor (technically there's an IR filter BEHIND that filter, and then finally the sensor is behind that.) You never actually get to touch the real sensor (not without considerable disassembly of the camera.) However... as it is a pain and somewhat involved to disassemble and replace a scratched filter, you do want to take care not to scratch it.
1) Are you sure this is on the filter and not "stuck" pixels? Can you see it on the filter when you inspect it? You may want to pick up a sensor scope if you don't have one (you can find them at
B&H,
Adorama, Amazon, etc.) -- it's basically a giant magnifier that rests on the lens flange and it has lights on it. It gives you a highly magnified view of the sensor so that you can actually see the surface and determine what you're dealing with.
I'm looking at this sensor cleaning kit you've got in the photo. I've never seen it before.
2) You may want to pick up some Eclipse solution and Sensor Swabs (your camera has an APS-C sensor, so the "Type II" sensor swabs are the size you'd get.) They're made by "Photographic Solutions" and you can find them at most true camera stores (not big-box stores that merely sell cameras). You can also order them online...
B&H,
Adorama, Amazon, etc.
The solution is actually mostly methanol. It evaporates _very_ quickly and leaves virtually no residue. I never seen this NOT be able to clean whatever I find and I don't need to go back with a dry cloth to clean the residue... it doesn't leave any residue.