TJS,
Gotta disagree on getting promoted using starters clubs. While I was in the pro tier with upgraded clubs, I lost several matches online to "pros" who were still using starter clubs but playing from the middle tees. I myself was promoted to pro within a week of playing and using starters but upgraded first chance I got. That said you would definitely struggle in the master tier with starters as the hole distances are dramatically longer. I do agree that it will be tough to earn enough credits to upgrade playing tourneys though.
Regarding the rough, it makes a huge difference on consistency if you don't hit the ball dead center. It is much more exaggerated than it is from the fairway as it should be. Also playing out of the deep rough, your higher irons will fly a lot truer to distance as in real golf. It is virtually impossible to get a 3iron on the ball in 30-40% rough in real golf or WGT even if you hit it squarely.
As for upgrading clubs when you advance to pro tier, it certainly makes the game more enjoyable and is a very minimal cost compared to greens fees at your local course and you will have the opportunity to use them much more frequently than your real set at your local course. Try that on the wife and see if she'll buy it. :) If you can sell her and do get to upgrade, I'd suggest the Ping irons over the Taylor Made as they seem to be more forgiving and have a slightly higher ball flight that stops a bit faster.
Welcome to the site and good luck.