How many blood draws in short period of time before volume depletion/shock becomes a real issue? i understand i'll be getting a test which requires like 30 tubes to be taken, then will get more tests for three consecutive days.

You should be OK: You body holds about 70mL of blood per kilogram of body weight. Most vials for tests are about 3mL of blood, so they are likely drawing around 90mL. For perspective, when you donate blood you give 350mL. This takes about 3-5 days for your body to replace. The bottom line is that you will be fine with that much blood drawn, even if they do it several times.

Blood draws: 29 F from OH asks about blood draws and shock. Depending on your size one has to lose at least 2 liters(2,000 cc) of blood quickly before BP may change much. Bleeding slower over a few days much less likely to do this. Thee both makes more blood. Each tube may have 5 cc so 30 = 150 cc. Very unlikely to feel this over a few days or weeks. And they will check BP each visit i suspect.

2L blood loss=shock: The avg human has ~6L of blood circualting; shock starts after you lose ~2L (2000 mL). Each tube of blood holds only about 15 to 30 mL of blood (maximum), so to lose 2000 mL of blood means, at minimum, you have to have like 70 tubes of blood taken. That all being said, people donate a pint of blood (250 mL) monthly & recover. You can get vasovagal reactions from the needle, not the blood loss.