Yay, plenty of times. May have lost like 1 or 2 in each region she participated in (Hoenn and Kanto). Dawn has lost a lot more times then that as you may know if you've been watching the anime.
No, they don't age. Ash is still 10, and he will remain 10. Doesn't matter how many regions he's been to, he's still 10. The only mention of time in the anime is days and weeks, but that is pretty much it and they don't specify about it. Don't liek it, complain to Dialga, he's the one slacking on the job by fighting with Palkia all the time.
Lol, you misunderstood me. I meant it like a "COTD" type of deal, or just somebody random that's not a main, recurring, or somebody we've seen more than once.