Yeah. The spin is more of a timing issue. To make the game more realistic they implemented the stutter-step spin. In games past and present you either spin in place (unrealistic) or spun while not really close to the defender (also unrealistic yet not quite as much so). In 2k3 they made it so you spin off of the contact of the defender (much more realistic). If you hit spin while you were a couple yards away from any one, you would just do a stutter-step, which sometimes was more effective than the juke button. If a defender was close, your man would still stutter-step, but would then spin when the defender touched him, making for a more realistic presentation of the NFL and less like the video games we're all used to playing. NFL 2K series makes you think NFL football, not video game football.
As for how many moves we can chain... I haven't heard yet either,
.... But I'd imagine how ever many buttons you can press in quick succession before a the first move animation is complete.-- No more than a couple.