My background is piano, and since recently, also keyboard, although without a pedalboard.

I notice that the Yamaha STAGEA D-DECK and the Roland ATELIER Combo AT-350C can be bought as a 2-manual keyboard alone without a pedalboard. I thought that they would be adequate initial learning vehicles, with the pedalboard (perhaps?) coming later.

Or do you have any other suggestions for a beginner who is afraid of pedal boards?

Lots of musicians use organs without pedalboards. Probably the expression pedal is more important because a lot of people use their left hand to play bass. But in the long run, the pedals are a benefit and I think you'd be doing yourself a favor to learn them.

There are some very basic Pipe Organs with only a single manual, or in some cases, 2 manuals without pedals. Mind you, they're harder to play, as you can't hold a pedal note or run while you use your left hand to change stops or presets. But then, most of these very small organs don't have many stops to play around with anyway.

Pedalboards aren't as scary as they look! ...easy for me to say- my degree is in organ :P

Short answer to your question, yes- an organ without a pedalboard is certainly still a musical instrument.

Longer answer: remember that organs and pianos (or keyboards) are completely different instruments and are played differently. One big difference is that the left hand isn't usually used to play the bass notes, as it is on the piano. There are a list of other differences, too-- notes don't decay on the organ, the organ has different stops that provide different combinations of timbres, etc.

I strongly encourage any pianist to learn organ, if nothing else, because it's a neat instrument. But you'll also make yourself substantially more employable for wedding gigs, or even a church gig.

There are a number of beginning organ method books designed for pianists to learn how to play organ (...yes, even the pedals!) quickly. Joyce Jones wrote a book called the "King of Instruments" published by MorningStar. It's only about $25 and is a great introductory course.

...And, of course, since it doesn't sound like you have a pedalboard at home... Usually churches are pretty nice about letting people practice on their organ if they're confident that you'll be respectful of the instrument!

I used to play organ and all I can say is it depends what you want to play on it. If you do get a pedalboard make sure you get one that goes to the f above middle c.