if you would care to read my post(s) properly you would find all the answers to all your questions
but maybe a long post w/out code isn't worthwhile your attention

however that might be, my professional & home experience based on

• having had a N900 for the last 3½ yrs - more then 2½ of which w/ power kernel, running pretty stable (certainly without crashes during GSM calls )
• having had many crashes (including in the middle of GSM calls ) since 22nd of September when i did a fresh install with the configuration that run fine for months before except adding CSSU(-thumb) according to TFM.
  the previous config only run the most recent version software installed w/out CSSU whatsoever

tells me CSSU doesn't work (for me)
thus i'm going to scrap it and re-flash Fremantle and re-install the same packages as before 22nd of September
sorry if i'm not good enough for your perfect software
guess

says it all... user has to abide by your perfect code or can go to hell
nuff said