Hi Hinari, no I don't get hot flushes since being on HRT, and I intend to stay on it for as long as possible so not bothered from that point of view! If I get too hot I just put it up in a bun or tie it in a plait.
My dad went grey very young, and both my daughters (aged 20 and 24) have a fair few silver strands sprinkled amongst their very dark, so I think they take after me. The difference is that they're both determined not to start dyeing, so they won't have the dilemma we have. My mum, who's 83, is still dyeing her hair - arrrrggghhhh!