My goal is to create a bot that would listen to the bitcoin network for a list of specific transactions associated with specific bitcoin addresses.
There is a pull request that adds support for watch-only addresses to bitcoind :
https://github.com/bitcoin/bitcoin/pull/2861. This PR allows to track transactions and balances without having to know and keep associated private keys in the wallet. Unfortunately, it is unclear when it will be merged.
It is also reported that people are using this in production (custom version of bitcoind).