Add additional subscriber to Transactional replication

Hi All,

Current scenario: Site 1 (Publisher DB) --> Site 2 (SubscriberDB) -- Transactional replication is setup

Now,we need to add another subscriber at Site 3. 

We plan to initialize the 2nd subscriber using a Backup. (http://msdn.microsoft.com/en-us/library/ms151705(v=sql.90).aspx). Currently, allow_initialize_from_backup is already set  to 1.

While adding new subscriber, I plan to DISABLE DISTRIBUTOR CLEANUP JOB temporarily to prevent removal of transactions from the distribution database. 

Further, we need to setup a filtered replication from this 2nd subscriber.

Questions:

1. Is there a downtime (even a small one) needed during this initialization using backup?

2. What other risks are seen during this kind of setup?

3. If I use the steps at http://msdn.microsoft.com/en-us/library/ms147834(v=sql.90).aspx to add the subscriber,
it will by default create a push replication, am I correct? (as that is what I want)

any help is highly appreciated!!

Thanks.