Figuring out how to make Apache Reverse Proxy do what I need it to do took longer than a couple minutes, leaving this here for posterity. Reverse Proxy for servers running on other ports. Shows use of subdirectory in ProxyPassReverse declaration.

reverseproxy.conf

<Location /sabnzb>
  order deny,allow
	deny from all
	allow from all
	ProxyPass http://localhost:8080/sabnzbd
	ProxyPassReverse http://localhost:8080/sabnzbd
</Location>

<Location /couchpotato>
	order deny,allow
	deny from all
	allow from all
	ProxyPass http://localhost:8082/couchpotato
	ProxyPassReverse http://localhost:8082/couchpotato
</Location>

<Location /sickbeard>
	order deny,allow
	deny from all
	allow from all
	ProxyPass http://localhost:8081/sickbeard
	ProxyPassReverse http://localhost:8081/sickbeard
</Location>

<Location /plex>
	order deny,allow
	deny from all
	allow from all
	ProxyPass http://localhost:32400/web
	ProxyPassReverse http://localhost:32400/web
</Location>

<Location /torrent>
	order deny,allow
	deny from all
	allow from all
	ProxyPass http://localhost:8083
	ProxyPassReverse http://localhost:8083
</Location>