I don't think it's normal that they don't have caps. If you bought it new, I'd ask the dealer for them.
For the 2 outlets, you have 3 options:
1) Plumb them together yourself. About $25 and some work. Forum member, OldCoot, did it:
Forest River Forums - OldCoot's Album: Connecting holding tanks
2) Get a "WYE" and connect your hoses together:
3) Just move the sewer hose.
I do #2 and just carry a bit extra sewer hose for sites. It's really an easily solution (not as easy as plumbing them together- but I don't have the skillz for that!).