Well, Minato, by all indications, is more skilled with it. For instance, Hiruzen requires physical contact, Minato does not. Hiruzen struggled to seal Orochimaru, Minato sealed half of Kurama, who's chakra far outweighs Orochimaru's.
Heck no! I don't count them because a top 10 is about who's stronger. A suicide technique does not make one "stronger" than another person. It's mutual destruction, meaning it only makes one equal others normally far ahead, which is why suicide techniques should not be considered.
Here's a fun fact, Minato could use RDS to seal Guy's ability to use the gates, leaving only base Guy to deal with, who can be easily killed by Minato.