Hi James,
I don't know if you have noticed the following in C. Scott's response
At any rate: in your configurations you have URL and HTTPProxy set to the exact same string. This is almost certainly not right. I believe if you just omit the proxy lines entirely from the configuration you'll find things work as you expect. --scott
but I could not help but notice the error too. AFAIK setting these variables instruct both software to use http://192.168.56.63:8001/ as a forward proxy which is NOT what you have there. HAproxy is a reverse proxy software, not a forward proxy (although you can abuse it to achieve that functionality). In the setup you describe there is no need for forward proxies so neither parsoid nor mediawiki need a proxy configuration.
I also don't think you need RESTBase as long as you are willing to wait for parsoid to finish parsing and returning the result. It should be fine for small articles, but as these grow larger, you will start having various performance related problems (for example you might have to adjust haproxy timeouts). But from what I gather, you are not there yet.