Am i taking the right approach

Having done a lot of this, I would:

1. Set up an ssh-key, to log in automatically without Expect - as a non-root user.
2. Write one Expect script for each of the (few?) commands that are interactive.
3. Write one straightforward wrapper to tie it all together.
4. Enable the non-root user to run the wrapper with sudo.

Something like this:

ssh admin@host "sudo /path/to/wrapper.pl"
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Where the wrapper might:

...
die("...") if system("/path/to/cmd1.sh")!=0;
die("...") if system("/path/to/interactive-cmd-exp.pl")!=0;
...
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