If you only have one coax run coming from the dish to the receiver, then that is a separator and not a splitter, The diplexer would need to be used before the separator
To check if you need aim your dish 9 degrees to the west, cover both outside lnb's and see if you are still receiving 119. If you only get 110 you need to re-aim it.
You would need the adapter to view live tv or dvr recordings on the receiver. You shouldn't need any thing if you want to view on demand material. And you will not be able to view anything from a EHD no matter what your setup is.
You may be getting 129 on the wrong eye of you lnb(s). Cover both outside eyes and aim for 119. Once you find it, uncover the others and fine tune for 110 and 129.
Did you try to change batteries? I had Dish remotes with would stop working on the SAT input but would still work tv. Cleaning connections couldn't hurt either.