manage WS and MSA REPLICATION

we will build the MSA replication way from Logical connection of already existed WS toward a replicated database, I still feel some conflicts, would you help please to understand some issues

When creating replication definition, if we add "replicate DDL" as follow:

create database replication definition repdef

with primary at Logicalconnectionname.databasename

replicate DDL

Does it mean that the replication will be bidirectional??

The already existed WS replication replicates the whole database by setting sp_reptostandby ‘all’

I want to replicate the same database and its transactions to the MSA subscription but don’t want them to return to the replication definition

- The WS is managed by a replication server, we will build another replication server to manage MSA, after building a route between two rep servers, what should we do with the RSSD database? do we need to update it to be replicated, and define a rep agent for it??

- when installing the rep server that manages MSA using rs_inti, the connection toward both rep definition and subscription will be built automatically, is it right? I think it is a physical connection? Do we need a logical connection in MSA as we will use it as standby application (i.e the subscription will not use unless we did a switch role to it)

- while installing a rep server when we define the primary database, do we add the logicalconnection name.the databasename?

- Would you please suggest some tutorials about doing switch over in MSA, the switch over in WS replication is simple, I think it is not in MSA.