Hi!
I'm not actually a VB programmer, but I looked at your questions and just had a couple of ideas on how I would do it. Remember, these are only suggestions. :D
2. Must contain 3 numeric characters
You could test each character, then increment a counter if it encounters a number. After all the characters has been checked, compare the counter if it is greater or equal to 3, then the condition passes.
3. No repeated phrase.
Test each character, if the character is a number, skip it, else put it in an array. Append each found character to the array. After all is done, compare the first character with the other characters in array. If there is no match, the condition passes. If it finds a match, get the second character, check with the other characters in the array. If there is a match, the whole condition fails. If no match was found after the second check, then the condition passes.
4. Lowercase
I think there a function for checking this. If not, get each character, check its value, (ex: uppercase is 41 to 5A), if it falls under the range of the uppercase characters, then the condition fails, else, continue checking.
I hope it made sense.