I just ran infected with us going a bit over an hour or so. We did in fact complete it. Infected is probably the easiest of all STF. I know you have said that you really have no time for a fleet, but maybe that is what you really need to do in order to be able to do all the STF. Get with a fleet that does them regularly as they would be able to help you though them. Using ts or vent is suggested to communicate though. Chat is available but is very limited when you fighting.
There should be two versions as long as the loot in a RA run is for RA only. Don't see why this would cause an exploit problem.
Having to drop the other version is rediculous. You should be able to have both in your quest log.
Sorry if I derailed your thread. I was trying to suggest a solution to the root of the problem which is people frequently dropping out. Not the symptom which is having do a whole new run.
This is no longer the case. It USED to be that completing the RA version would get you a completion for the VA version as well (so long as you had picked up the mission). However, with the new borg loot, people were getting 2 sets at a time so they changed it in the latest update. You can now only pick up 1 version at a time. If you pick up the RA version, the VA version is unavailable. And vice versa.