Two basic things to keep in mind:
- Traffic is distributed packet by packet
- All packets associated with a given “conversation” aretransmitted on the same link to prevent mis-ordering
That second point has some variability between Operating Systems and implementations as to what is a "conversation" so the answers to some of your questions are not always the same. Generally if there are a lot of "conversations" the link will perform well but single stream benchmarking between two systems will be limited to what a single link can provide.
Ref: PDF IEEE 802.3ad Link Aggregation (LAG) what it is, and what it is not
