70c is pretty warm, but *shouldn't* be fatal. I've personally never used ballistix, so I can't really comment on them as a brand., althought they do have a decent rep.
Are you using a stock cooler on your CPU?
40c idle is ok, yet it's the load temps that are more accurate. 85tjmax should be a an ok buffer. 68c is a little high. It's still in the safe temp range, but cooler is better. Are you running stock speeds or OC'ed?
It sounds like your airflow is insufficient atm, so the extra fans are definitely a good idea.
As an example, I just got a new case with fans everywhere and compared to the case I replaced, I'm getting 3-4c lower on my CPU idle temps and 5-10c cooler across everything else just from improved airflow alone