GravityFlux. You asked for feedback on the sheet. Aside from a small bit, we couldn't notice anything wrong with it. We quoted that here:
[quote]The Gulf War ended, and he had nothing more. So, he requested for UN Duty. When his request was granted, he joined the UN Peacekeepers as a Canadian officer, fighting in most future UN deployments, such as Afghanistan.[/quote]
Considering his age (you changed it from the original 37 to 36), it makes even less sense to have any mention of the gulf war. We'd suggest highlighting a bit more on more recent wars instead, and if you feel the need to mention the gulf war at all, make it instead relate to his reason for joining military.

[quote]But then his prime time came. He was selected as a Strike Leader for the Catherine Langford's military forces. He found out that he HAD been a candidate for such programs earlier, due to his improvisation skills and tactical experience, but he had been too busy, stuck in Afghanistan, where most of his time fighting was spent.

He was quickly briefed on the SG program, and has had enough time to cope with it and learn about it. Immediately after he was selected and briefed for the program, he was freshly promoted to Colonel for his services.[/quote]
This section feels a bit sparse, and it doesn't entirely make sense. If Homeworld Security and the IOA wants someone for the program, they won't care much if (s)he is busy in some war merely affecting a minor Earth nation or two. They've got the clout to take pretty much anyone in the SG-participating nations' militaries. Of course, it could've been that he said "no" till he felt "finished" down there. That would build up a stronger impression of his stubbornness. 

Pretty sure that anyone going offworld, especially in a leadership role, would go through more than a quick briefing about the SG program. We'd suggest adding a short tour or so as an SG team member/leader. While there's been no mention of the USAF having any Canadian SG-team(s), a lot could have changed as IOA and Homeworld security rose to more prominent positions. We at least wouldn't send someone as a leader on a mission like this unless we've tested their mettle against aliens.

One final question: Why was he promoted? They generally don't promote anyone simply "for their services". Maybe he did something to make him truly stand out during his SG-initiation? 

We'd usually tear far more holes in character sheets, but we're not a GM in this RP, and there wasn't much else worth tearing at. The rest of the sheet just did not have anything that we saw worth picking at. In other words, we liked the rest of it.