Add additional circuits after 3-way switch
You are correct -- there is no way to add independent circuits off the second switch.  Here is another way to look at the switch configuration using three-way switches (the black wire being the 'white wire taped black' in your diagram, the red wire to the light being black, and the neutral being white).



As you can see, the right-hand switch -- where you want to branch from -- does not receive the hot connection independently of the left-hand switch.  You'll have to run an additional, independent 14/2 through the conduit, or replace your 14/3 with 14/4 as Tyson suggests.