I have hundreds of JBoss apps fronted by F5s without Apache. The only real benefit, IMO, that apache provides in a JBoss deployment is better request logging and is really the only reason my organization utilizes it at all in front of JBoss (when we do, we just use mod proxy, not mod jk. I see no value in mod_jk at all). Apps that do a good job of logging themselves don't really need that though.
So the answer is yes, perfectly doable, it just really depends on how much you rely on those request logs from an operational standpoint. You can provide the same logging via the F5, but to have the available options that Apache provides there, you'd need to do it in an iRule and you'd probably want to send those logs off to splunk or something via HSL.
As for monitoring, my preference is for the application to provide some sort of status page that will monitor the health of the application itself behind the scenes. That way the monitor from the F5 is just getting a "good/not good" response from the status. This is true with or without an apache. Apache itself doesn't really have the robust level or variety of monitoring that a true load balancer, like an F5, has.
Regarding persistence, I just use cookie insert by default for web apps that require persistence, but for webservices persistence shouldn't be required at all.
The thing that an F5 gives you over an apache (even with apache) is the ability to more easily remediate issues. Specifically like applying an App Firewall, web acceleration, analytics, etc.
You can do some or most of that with apache as well, but changes to apache require a restart/reload (depending on what you are doing). Change to an F5 proxy happen on the next new connection.
Cirrostratus
