I found with my RV082 that whenever I changed the operating mode from either Load Balance or Smart Backup mode to WAN1/DMZ mode , or even switched between Load Balance and Smart Backup, I had to do a factory default reset. It seems that when those mode changes occurred, some settings (that were no longer visible) were still active, and interfered with operation.
For example, when I changed from two load balanced DSL lines to a primary Comcast HSI connection with a backup DSL connection, my top download speed was only about 1.5 mbps even though I had a 12 mbps primary connection. That happened even with QoS settings disabled. After doing a factory default reset everything worked as expected. If you have not already tried a factory default reset, you may want to try it.
As for your https problems when doing load balancing, you just need to do a protocol binding for https to one WAN interface. Doing that will not keep the automatic backup feature from working should that interface go down (when that happens, the port/protocol rule is just ignored by the router).
I was going to provide a link to Cisco on-line documents that explained how the dual WAN feature is managed, as well as a description of how to do the protocol binding, but Cisco in their great wisdom has pulled that documentation from their web site. I suspect that the reason is that the user interface (and many of the options) are different on the current hardware version 3 devices, and the old on-line documentation showed the old hardware version 1 and 2 user interface. So, rather than just provide additional documentation for the newer devices, they simply pulled all of the documentation... problem solved.
The best I can do is to show you an old screen shot that I had posted in another thread that showed how I setup the protocol binding for https when I was doing load balancing (I also had to do the same thing for SSL POP3/SMTP sessions). This worked perfectly for me, and it in no way caused any kind of slow down for SSL (or any other activity). Of course, if you have one of the newer hardware version 3 devices, you will not see this exact setup page, but you should be able to find a setup page with similar functionality.
History does not long entrust the care of freedom to the weak or the timid.
-- Dwight D. Eisenhower