Hello,
The difference between e*Way and e*Way Connections: Actually in a e*Way there are two layers, one is communication & other is data transformation.But with 452 version Seebeyond have separated these to just reduce the load.So in e*way connections you will delt mainly with configration only.
Your other question is differance between multimode & bi-directional...whenever you are using e*Way connection for your configartion, then you have to select multimode exe that is stceway.exe instead of stcgenericmonk or stcgenericjava.Where as bidirectional e*Way is whenever you are using same collaboration file for input as well as output.So basically these two are not same.we can't differniate between them.