Questions on Group Users stats

There is nothing specifically regarding Group User stats in the FAQ or other discussions I searched. So for my and newbies' sake, I want to make sure I understand how they're calculated, especially since some groups use group user stats to determine when someone should be removed from the group. So here's my current understanding and questions of Group Users stats:

Sent & Received # of games: A game Sent or Received is counted as a fraction of a game if more than one group or a whitelist is selected for a GA. Example: One GA for a group and a whitelist is created, and a winner marks the key as received. The gifter's Sent game count and the winner's Received count is increased by 0.5 (One game divided by two "groups"=0.5).
Do <5 entry wins not count toward Sent/Received game count?
Is the Sent and Received game counts rounded up to the nearest tenth of a decimal place? Example: A GA for 4 groups is redeemed, so would that add 0.2 or 0.3 to Sent or Received counts?

Sent & Received CV: This appears to show the regular CV amount, NOT real CV.
Multi-group GAs have their value divided by the number of groups/whitelist selected.
Example: If a $10 retail price game is given away to two groups then its value is reported as $5.
If less than 5 entries are received for a giveaway, does this mean that NO Sent AND Received CV $ are added for the gifter & winner? The only relevant FAQ reference is this:

If a giveaway is invite only, region restricted, or limited to a whitelist or Steam group, it will only add contributor value if it receives 5 or more entries.

Gift difference: Clearly is the # of gifts sent minus gifts received.

Value difference: Clearly is the CV sent minus CV received. This is how groups' user lists appear to be sorted. If 2 users have the same value difference, is there a secondary sort, such as Gift Difference?