Unfortunately the regular WinBoard edition does not fully support Chu Shogi. Although WinBoard and XBoard internally support the same piece types, only XBoard supports images for the piece types beyond the first 22, which were added to support Chu Shogi. The problem is that the XBoard (scalable) graphics cannot be used by WinBoard: the latter needs MS bitmaps, a separate set for each board size. Making those is quite tedious, and I never got to doing it. Of course WinBoard can use external bitmaps, but in WB 4.8 only the first 22 piece types had filenames defined for them, (names like k49o.bmp), so it was no help for the missing Chu pieces. This at least has been fixed in WB 4.9, where an alternative naming system for external bitmaps is supported, which would work for all piece types. Someone would still have to make the bitmaps, however. The -inscriptions option that can synthesize oriental-style piece graphics 'on the fly', by rendering kanji on a blank tile, also is only supported in XBoard.
The point is that there already existed a WinBoard fork (the 'Alien Edition') that does support Chu Shogi. I put a binary of this version in the Shogi-variants package. It does draw Chu pieces (as well as other large Shogi variants) by rendering hard-wired kanji, or (in some board sizes) using on-the-fly synthesized mnemonic graphics. Until the WinBoard front-end is thoroughly rewritten (to at least support transparency, so that bitmaps can be created by rendering the XBoard SVG graphics) the Alien Edition is the recommended way for playing Chu Shogi on Windows.
As for the marking of legal move targets, the option -showTargetSquare and -highlightDragging have to be configured as true. Only the latter can be set through a menu dialog. The former can only be set from the command line (or as Additional option in the Startup Dialog), but is persistent, so that you only have to do that once. In the binary package I pre-configure it as true, but the compiled-in default is false. On FICS they consider highlighting target squares as 'computer help', and thus cheating. So I disabled it in ICS mode, to prevent WinBoard from being banned as interface for FICS.