multiple hot standby streaming replication scenario with "rotating" the primary server

Hi,
I'm trying to set up at least 3 servers using hot standby streaming
replication. I'd like to have one primary and 2 secondary (on 2
different locations in case of a desaster in the server room).
A primary
B secondary 1
C secondary 2 (on a different location that A and B)

Are the following actions in case of recovering to any of the standby
servers (B or C) correct ?

1. primary A crashes/maintenance or whatever
2. creating the trigger file on B brings this server to life.
3. stop server on C
4. make base backup on B and install it on C and A (if already available)
5. change primary_conninfo in recovery.conf on A,C to reflect new primary B
6. start server on A,C

These actions should all be automated, since I have no redundancy
between step 1 and 6, so in case something happens to the just
switched over new primary, I have no up to date server to bring up
from standby. Making base backup takes ~10 mins, installing probably
also about 10 mins, so I have 20 minutes, where nothing should happen
to B :-(

But maybe I'm also missing something.

regards
Gerhard