well, ill answer my own question maybe. i found some "generic carbide recomendations" for 304 stainless.
90sfm - 1400 (my first possible mistake)
feed rate - 11ipm (second mistake)
so it seems i did indeed his some sort of HSM sweet spot on the 1/2". i need to be going slower rpm with more aggressive feed for the 1/4" to work well with only 3000rpm.
make sense? seems to explain the overheating and glowing tool - its just rubbing on the work, not cutting.