As T-Block says, work with what you have at your disposal. It is generally easier to transfer from piano to organ or keyboard than the other way around.
First, since the amount of pressure that you use on the keys determines its volume and tone quality you develop your fingers in a way that you can't on the organ. People who start on an organ often find it much more difficult to control a piano's tone.
Second, if you are playing solo piano, your hands have to do all of the work of melody, accompaniement and bass. It is again easier to let your left hand do less (or different things) when you start to transfer the bass to the organ pedals than to all of a sudden need to do more with your L.H. transfering from organ to piano.
But, organ technic is different from piano technic. It doesn't matter how hard you play the keys, they will remain the same volume until you move the expression pedal. Also, you don't have the damper pedal to help with tricky legato passages.
You do not need to completely limit yourself to one or the other. Concentrate on the piano, continue to try things on the keyboard -- and if your keyboard can do an organ sound without touch sensitivity you can practice organ finger technic on it and then continue to work at the organ at your church when you have the opportunity.
As far as the Technics brand versus Hammond. It doesn't hurt to get used to organs other than a Hammond. Not all organs have drawbars. Unless the Technics is strictly preset, most organs will have a set of buttons or tabs with such names as "Flute 8'" or "Tibia 8'" and there will usually be at least a 16', 8', and 4' -- these are equivalent to the first third and 4th draw bars. In fact, the drawbars on the Hammond are "Flute" sounds 16', 5 1/3', 8', 4', 2 2/3,' 2', 1 3/5, and 1' so buttons or tabs on a non-drawbar instrument can be used the same as those drawbars full on.
I've played every type of keyboard imaginable (o.K -- I play the world's slowest polka on an accordion -- I can either press the keys or squeeze but not at the same time). I'm glad that I have had that opportunity because I can sit down and play anywhere no matter which type of keyboard they have (unless all they have is that pesky accordion). You need not limit yourself to one or the other.