Once Wireless Redstone is back and updated, this question will become rather moot, as you can just offload the computer from the frame and send timed pulses through a wireless relay on the frame.
It would be nice to have a bundled cable version of a wireless transmitter/receiver, though.
As for liquids, how about using buckets as a black/whitelist point of ID, and only use source blocks? I've seen isolated cases of solo water sources not flowing when they should, so keeping that from happening shouldn't be hard to do.