1st road bike - compact v. traditional geometry, etc.

[indysteel]

What's your friend's beef with compact geometry? All that generally means is that it has a sloping top tube, which is what you're going to find on the market these days on most smaller frames. Some people--your friend perhaps--doesn't like the look of them and prefer a horizontal top tube. I do, too, to be honest, but from a functional standpoint, a sloping top tube just makes practical sense for smaller riders. So, I'd ignore that part of his advice.

Aluminum can ride harshly, especially if you ride crappy roads, but it's relatively inexpensive and readily available so I wouldn't rule it out. Test ride as many bikes as you can. There are a few mass produced steel bikes out there--Jamis comes to mind. I have a WSD steel Bianchi myself that I love, but it's no longer in production.

Carbon would also be worth considering, but don't blow your budget just because of your friend's biased (in my view) opinion.

[warneral]

I'd definitely ask this in the Triathalon forum. I personally went from aluminum to steel (both with carbon forks), skinnier tires and better components. A better bike is a better bike! And worth it IMO. But if you're just wanting it for Tri sprints, perhaps you don't need the top of the line bike