How hot is too hot?

I set up the controller in my SV25 to keep the PS at 35, the CPU at 40, and the chassis at 30 (all deg C). Reading the data sheets for memory, drives, etc. everything is rated at much higher temps (drives are 55C, memory is 70C, etc.)

I the fans would be much quieter at idle if I upped the setpoints, but I don't want to do any damage. I'm thinking 43 for the CPU, 45 for the PS, and 50 for the chassis exhaust.

I don't overclock, I don't game, the PC doesn't even have a monitor. The fan control is closed-loop so there's no risk of exceeding the setpoints (at least, very little risk).

Thoughts? Does anyone else allow high temps for the sake of silence?

I posted this in the "Cases & Cooling" forum first, but it seems that's geared more toward keeping things cool than keeping things quiet.