Ah, it is good to see an astrophotographer with a Pentax. You asked about Remote Assistant at just the wrong time for me.
I just came in from my little home built observatory after a frustrating session with Remote Assistant. For some reason, after working in the past, RA won't recognize my modified K110D. Actually it knows the camera is present since if I power off the K110D, RA pops up a message about the power switch. When RA is started the display on the camera changes from "PC" to display shutter speed etc as it should. But the RA display remains greyed out. Also, the PC mode assigns a disk drive letter which lets me read the memory card.
I'm using the istD version of RA which was never blessed to work with the K1x0D. I brought the camera indoors to my home PC, same problem. Plug in my K100D and RA works with that, as it always has in the past. I reset the K110D, compared menus, etc and can't figure out why one works, the other does not. Unfortunately the K100D is my daytime camera, K110D has the filter removed and is intended for astro only. I've used RA with the K100D to take photos of birds at a bird feeder, I'd watch for a bird on a web cam, click the shutter remotely, view the results. It has a few bugs, but I only use a couple of functions (exposure, shutter button, auto save). I view the results with Pentax Browser to check focus.
I'm learning fast about using a DSLR for astro after 7 years with an SBIG. I built a timer box to cycle the exposures, based on a design by a fellow on British Columbia Island. I don't absolutely need RA, but just use it for focusing since stars are pretty small in the viewfinder.
I process raw files using Images Plus. The author added Pentax PEF conversion after asking me for a few PEF sample files to test with.
You mentioned wanting JPEGs, I could not get RA to work with anything but PEF.
Soon I will post my tale of removing the IR filter on the K110D...