So never mind me being uncomfortable, why make your colleague feel uncomfortable? CRM is all about team work,with me i think you'd be flying single crew on the next sector, although it sounds like you fly single on all of them
Why get personal. I didn't ask you if you are the type that always brings a ton extra fuel "just to be sure", although one might get the impression from "i always aim to be at least 1000' below the FMC generated MAX flight level"... Where did you get this arbitrary 1000' from?
in any event flying above OPT is normally counter productive
Not more counter productive than flying below. And there may be environmental benefits as well, that speak for choosing a level different from optimum, like more favorable wind etc.
It's really off-topic, but I just can't stand such unfounded personal margins. If Boeing wanted you to always operate at max alt minus 1000 feet, and deemed it unsafe to go higher, they would simply have programmed the FMC to show max alt 1000' lower.