Going to note a caveat to this: while some Mages may work to keep themselves fit, they're still not Warriors. Even at best, a Mage is dividing his attention between the physical and the mental. It's safe to say that no Mage, Rogue, or what have you is going to out-muscle a Warrior that himself focuses on strength.
There is a difference between going outside of a stereotype, and going outside of what makes sense for your class. While some characters within each class are stronger, smarter, more agile, etc. than others, there comes a point where you have to step back and consider if just what you're making makes sense. If you want a character that puts power-lifters to shame, are you sure that you really want to be playing a Mage or a Rogue?
Note: This is not an attack on Siv or Siv's character, but rather a note to ensure what's said here is not used for semi-ridiculous characters later.
I'd argue that on the account of combat rogues, but for the most part I'm right there with you. The, "rogues only use daggers" stereotype is really what I was protesting there. Rogues who're thugs are more muscle then stealth or poisons. I think a rogue like that could hold up against most soldiers as far as strength is concerned. Combat rogues are a very strength based group. Overpower a warrior? Nah. Hold their own, likely. I often do feel I should've rolled Siv as a warrior.
I did edit #7 to include your opinion.