OTP by email was deprecated deliberately - this was in the legacy SSL VPN appliance since (I believe) before the acquisition of the original vendor in 2008.
However, times move on. Where OTP by email used to be "the way that everyone does it", now it's getting too complex (what if I'm overseas in an Internet cafe or public kiosk and don't have the right roaming package to get email on my phone, or I don't have any on-prem mailflow anymore because I use the cloud, or what happens if the email goes to spam because it refers to passwords, etc). The more common approach now is to use Google Authenticator (which is actually nothing to do with Google, but is an implementation of the public RFC 6238 describing Time-based One Time Passwords) - this has a bunch of advantages, the biggest of which is that it's completely offline. If you find yourself somewhere where you have no access to email on your smartphone, as long as you have the smartphone itself and the time is approximately synchronised, you can still log in and get access to what you need. This is supported by the CloudGen Firewall and is the new way to use OTP for authentication. There are also options using RADIUS, some RADIUS server vendors also have the ability to configure multiple authentication factors, which the CloudGen Firewall can take advantage of.
The changeover in products between the legacy appliance and the Firewall-integrated SSL VPN made it a perfect time to remove (or not port over) some features which were not commonly used and do not make much sense, OTP by email was certainly one of them and the other missing features you refer to may be in a similar situation. If there are other features which you feel are missing and are still relevant today, then you can submit them to our feedback portal (http://netsecfeedback.barracuda.com/) where they can be reviewed by Product Management, voted for by other customers so that we can get a measure of how important a particular feature is by how many people want it, and potentially implement the feature.