I've used the red RTV on my exhaust with no problems. Your exhaust gets hot but not when compared to the temperature resistance of silicone.
I thought the tip to use silicone noodles was interesting. I've used the "smear technique" forever and it seemed to work. I thought it would give me more sealant than I needed but when changing an oil pan gasket recently, I found it it didn't use any more than smearing. Obviously you can't use silicone for the main caps to pan seal but next time, I'll try making the rail gaskets rather than using the cork gaskets as they are so delicate. The uprated pan gaskets sound a lot nicer than the old ones though.