ether 5'6 or 5'4
Sure, but it is usually with the approval of the team's manager.
The MLB pitcher that was nicknamed the "Rocket" was Roger Clemens.
In MLB for the 2009 season, that is Jamie Moyer of the Philadelphia Phillies at age 46 (born November 18, 1962).
The heaviest pitcher in MLB History is definitely Nolan Ryan.
There is nothing I have found in the MLB rules that would prohibit a pitcher from a pitching motion similar to that of a softball pitcher. Actually, the underhanded motion was the rule when Alexander Cartwright came up with the rules of baseball in 1845. I have included a link, named 'MLB Rule 8', to the MLB rules concerning the pitcher on this page.
MLB rule 1.07 defines the dimensions of the pitcher's plate as 24 inches by 6 inches. There is no dimension given for its thickness, or depth.
The pitcher was Bob Gibson. MLB lowered the mound in 1969. In 1968, Gibson went 22-9 with a 1.12 ERA and 268 strike outs.
The smallest-in-history MLB player is the 43-inch stuntman Eddie Gaedel, who played for the St. Louis Browns for only 1 game in 1951. He had the smallest strike zone in MLB history- about 1 1/2 inches!
Whoever told you this lied to you. Ted Williams retired at the end of the 1960 season. Assuming that the pitcher in 1960 was 16 (meaning born in 1944), he would have been 62 years old pitching in the MLB in 2006. That never happened. Unless there was a MLB pitcher that pithed to Ted Williams in a celebrity game or something like that... but never happened when they were all in the MLB