Answer:
Yes. Roethlisberger's QB rating of 22.6 in Super Bowl XL is lowest rating of a winning quarterback in Super Bowl history. The previous lowest QB rating of a winning Super Bowl QB was John Elway's 51.9 in Denver's victory over Green Bay in Super Bowl XXXII.
Yes. Ben Roethlisberger was the youngest player EVER to win a SB.
Three years later in Super Bowl XLIII he had a 93.2 passer rating beating the Arizona Cardinals. Ben Roethlisberger won two Super Bowls in his first five years in the NFL.
Actually that answer is wrong.
The worst QB rating held by a QB in a Super Bowl is Craig Morton in Super Bowl XII with a rating of 0.0.
Ben Roethlisber only comes in at 7 in the Top 10 all time worst QB Ratings in Super Bowls
List is as follows:
1. Craig Morton, Denver Super Bowl XII
4 of 15, 39 yds, 4 INTs, 0.0 rating
2. Kerry Collins, Giants Super Bowl XXXV
15 of 39, 112 yds, 4 INTs, 7.1 rating
3. Earl Morrall, Colts Super Bowl III
6 of 17, 71 yds, 3 INTs, 9.3 rating
4. Fran Tarkenton, Vikings Super Bowl IX
11 of 26, 102 yds, 3 INTs, 14.1 rating
5. John Elway, Denver Super Bowl XXIV
10 of 26, 108 yds, 2 INTs, 19.4
6. Billy Kilmer, Redskins Super Bowl VII
14 of 28, 104, 3 INTs, 19.7 raing
7. Ben Rothlberg., Pitt. Super Bowl XL
9 of 21, 123 yds, 2 INTs, 22.6 rating
8. Craig Morton, Dallas Super Bowl V
12 of 26, 127 yds, 1 TD, 3 INTs, 34.1
9. John Elway, Denver Super Bowl XXII
14 of 38, 257 yds, 1 TD, 3 INTs, 36.8
10. Ron Jaworski, Phil. Super Bowl XV
18 of 38, 291 Yds, 1 TD, 3 INTs, 42.6
Source:
http://blogs.cjonline.com/index.php?entry=1987