yes, I would say that those temperature are a bit hot. but if they’re not climbing on a regular basis (the Idle ones), then I think you’re okay for now. I would try and add some additional fan or fans to help cool the system, because as long as the case of your box isn’t large, those temps might be because of the parts being squeezed together and venting hot air all the time in the same place and there is no compensating mechanism, well, at least not strong enough apparently.
My temperatures are in those ranges when reading from the BIOS and I never seem to have any problems. I’m running an Athlon XP 2700 and get 50c in normal running (don’t game much, so average use).
As for your CPu temperature problem, just buy a new / bigger / copper Heatsink and fan (or CPu cooler) yes the older athlon originals and athlon XP’s were made to withstand higher temperatues, my old 1333MHz T-bird Athlon ran at just under 70 Degrees C idle and 78/79 on full load, and as far as I know it still works today (As I sold that computer to somebody who lives down the road )
Newer CPu’s shouldnt see more than 60 Degrees C, and definitely not over 70. 45 - 55 would be an ideal temperature for a fairly modern CPu, hell my Athlon 64 3200+ here, overclocked more than 25% (2GHz - 2.51GHz) runs nicely at 38 Degrees C idle and 54 at an absolute maximum under heavy load for hours. And thats on a small AKASA copper base but mostly aluminium heatsink, with a 50mm fan with auto speed sense control.