Customer comes in and has a currency exchange for $120. Then he withdrawals $12,000. Would I include the $12,120 on line 22 with the account number or just the $12,000 and list the $120 on page 5 as only currency exchange?

$12,120.

Would this change if the $12,000 was a deposit for a business?

Depends. If the $120 was on his own behalf and $12,000 was on behalf of the business, you would have two Part I's for him of $120 and $12,000 respectfully.

If the currency exchange and the deposit were both on behalf of the business, then you would have a single Part I for him at $12,120.