I wouldn't run the line back inside. The condensate pan is outside already, so re-routing the drain line back inside won't keep the waste water from being outside to begin with. It would be a pain in the butt, not accomplish what you want and asking for water damage. I think you are going above and beyond what most people even think about doing to be safe. As long as you don't tell anyone you're growing I think you'll be safe.
My first grow is about a month into veg and just started to really smell. The room they are in has a window unit that I sealed with foam board, foil tape and caulk. I didn't bother with the extra step of pulling the unit apart and sealing, so you're one up on me. There is absolutely no smell outside. There is lots of smell inside! My gf was stressing about the smell inside, so I put my ionizer/ozone generator on a recycling timer in the room next to my grow room. On 2 minutes off 20 minutes and absolutely no smell unless you go into the room. I have no exhaust/intake/carbon filters because I don't care if the grow room smells and draw air in and out the rest of my house for air exchanges. I'm still a noob, so I don't know if this will work in flower, but I think it will. I'm still adjusting my recycling timer to get to the point where I produce just the perfect amount of ozone to kill that delicious smell. When I don't smell ozone or weed, it's right on.