Statement 1 is Correct: The four Grand Slam tournaments (Australian Open, Roland-Garros, Wimbledon, and US Open) collaborate through a shared governance structure called the Grand Slam Board (GSB). The GSB is responsible for coordinating activities of mutual interest, including maintaining the unified Grand Slam Rule Book, officiating, and managing relationships with governing bodies like the ATP, WTA, and ITF.

Statement 2 is Incorrect: According to the Grand Slam Rule Book's "Open Competition" section, entry is not open to all internationally ranked players. A player must have a ranking of 500 or better. While it is true that minors under the age of 14 are not eligible for entry, the ranking restriction means that simply being internationally ranked and above 14 is not sufficient for entry.

Statement 3 is Incorrect: While each tournament draw has a fixed maximum number of wild card slots (e.g., 8 wild cards in a standard 128-player singles main draw), there is no restriction on how many wild cards a specific individual can be granted over time. The official rulebook explicitly features a "No Limitation" clause, stating that there shall be no limitation as to the number of Wild Cards a player may receive to compete in the Grand Slam Tournaments.

Therefore, option C is the correct answer.