SQL Server Lock Escalation clarity required
1: No, the trace flag is enough to disable lock escalation. No need to do an ALTER TABLE for every table. If you had to do an ALTER TABLE, then the trace flag would be meaningless.  Per the official documentation on that trace flag:

Disables lock escalation based on memory pressure, or based on number of locks. The SQL Server Database Engine will not escalate row or page locks to table locks.
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...trace flag 1211 prevents escalation in every case, even under memory pressure...

2: No, no need to disable page locks in order to get rid of lock escalation.
I, of course, agree with the others about how you don't want to use this trace flag. I mainly wanted to provide an answer to the question you posted.