TSP means total skill points, which adds up the numerical values of a player's skills. I'm unsure, but the stamina and free throws of a player might be ignored. Someone correct me on this.
DMI means deliberately meaningless index. To my knowledge, there isn't an accurate formula about how the numbers are calculated, but it can be a bit useful. When a player (for example, an 18 year old draftee) receives training, their DMI will increase (as they get skill pops). Another thing that increase DMI is the GS, or game shape of a player. If 2 guys were to have similar salaries, it could be the result of training, GS, or both. I hope I'm making sense.