My question is, how can a non-mining entity that is part of the Bitcoin economy and/or ecosystem show their support/non-support of SegWit?
The best thing a non-miner can do to support the network and signal their support for SegWit would be to run Bitcoin Core 0.13.1. You can see that currently 30% of the nodes on the network are running 0.13.1.
https://bitnodes.21.co/nodes/Actually there are already around 33% Segwit nodes ( NODE_WITNESS flag ) 1777 of 5434