It looks like you didn't mod your wii yourself?
If it boots directly into usbloader_gx, it means that priiloader was configured to do this. So the default settings of booting into the system menu have been changed.
Holding the reset button during boot is indeed the way to enter priiloader setup. In that setup it has an option to boot into system menu.
neek2o only automagically boots when you insert a sd card if you have bootmii installed as boot2.
bootmii launches armboot.bin in the sd:/bootmii folder. Older neek setups replaced that file by one that launches neek.
So, at boot, bootmii started, found armboot.bin and launched it. That loaded neek.
Modmii creates a bootmiineek folder under the COPY_TO_SD folder that contains the armboot.bin needed to launch sneek that way.
As you figured out already, you can install a channel to boot into neek. Before MMM is able to boot it, you need to select ios 236.
If you can't select that ios, it probably isn't installed.
The reason could be that you launch mmm from usbloader_gx instead of the homebrew channel.
Launched from the hbc, it should run on ios 58 with ahbprot enabled. Launched from usbloader_gx, it will probably run on ios 249 or 222.
So, try to install that wad again, and try to get rid of that Ticket (-2011) error.
I would try priiloader setup -> homebrew channel (or system menu) -> mmm (either try to install directly or switch to ios 236) (install ios236 if selecting it is not an option.)
Sneek2o + di isn't working for most people at the moment. You can try Sneek2o, and Uneek2o + di once you know your neek setup is working.