Can you use the same account for both services?

First you should find out why did it stop. You can check with Replication Monitor the history of your Agents, the history of the jobs and maybe event viewer and...

Do you want to replicate the schema or the execution of the stored procedures?

You can replicate to Oracle with no problems. And if you want to replicate all the inserts, updates and deletes made at sql Server, I would recommend transactional replication.

If you...

I would recommend to run the merge agent within the command line using replmerg.exe.

You can copy the parameters usend in the job wich runs the agent, and used them with...

When you run the snapshot agent, SQL places shared locks in the tables that participate in the publication.

That mean that you can select the table, but not modifing then.

If you...

Did you ever delete those subscriptions and then re create them again? Maybe they wasn't cleaned right.

Check resubscribing the servers to your publication.

Do you have a performance baseline? Do you know what the poerformance should be when everything is normal?

Check if you have any jobs running, or also can run profiler or...

Can you post the error message of the job history?

If you run the dts package outside a job, does you still have errors?

I don't think that it will exists. But you can query

select object_name(parent_obj)

from pubs.dbo.sysobjects

where xtype = 'TR'

AND Name = 'trigger_name'

TO know in witch table the trigger was define,...

Do you have any user available to execute backups?

Have you consider using log shipping instead of transactional replication?

You can run sp_helpdb without any parameter to know the size of all dbs in your server or also sp_databases. but to know the free size, you will have to...

I don't think the default value for a sp parameter is in any column. But I guess you can search in the text column of the syscomments tables, for the...

Do you have any error executing xp_sendmail?

It looks to more a configuration of outlook than a problem of SQL.