When I first started playing keys, I had to carry the K2000VP back and forth, it was my only keyboard. Since I now have additional keyboards at home and for gigs, I have been able to leave the instrument (also frees my wife and I up to go in her Miate if we are without the daughter and granddaughter that weekend).
I leave one complete setup at church (although it is well known that the instruments belong to me). Kurzweil K2000VP and PC2, Also a Tapco mixer, Trace amp, and Fender speaker cabinet, all set up. I remove power from all of the instruments (have a couple of UPS, and both turn them off and unplug all the power leads. I also have covers over them (the strchy kind). I've not had any problem with others, the only thing that has been moved is the bench seat. I also leave hard cases for both instruments, and a smaller case for all the accessories; for the occasional times that I have to move the whole setup out of the way and store it for special events. I do have all the settings on the amp and mixing board recorded.
Covering the instruments would not deter someone who was determined; but it is very useful in pointing out to most people - leave this alone!
Our pastor and music director both have made the point that instruments (indluding the church instruments) are not to be touched by those not trained. This includes sound equipment. When our kids meet, it is normally in the fellowship area, not in the sanctuary.
When I played bass, I left the amp and cabinet at the church, and carried the bass with me. When I was using a laptop computer with soft synths, I carried that with me, and left the docking station there.
If we are playing out somewhere else, I normally carry my portable gig setup, which is a K2661 keyboard with varioius combinations of powered PA cabinets, depending on the size of the area to be covered, and whether or not I am also providing PA for the praise team.
The big keyboards (88key weighted) usually stay at home or in my shop/studio.
I'll be 67 in a couple of weeks - I got tired of being my own roadie, especially in bad weather.
Jim.