(1) Missing the 'note' connection from the MVC to the SampleOSC.
(2) Missing the gate connection from the MVC to the SampleOSC
(3) Missing connection from gate to esync on MVC, as you're not using an envelope
(4) Possibly missing PolyOut module, if you want more than one voice
You can loop the ENTIRE sample using the MIDI gater, but as far as I can see, there's no way to define a traditional sample loop. For advanced sampling features, use the STS samplers.