I can successfully purchase the Force Track, as well as placing it. The first track that's placed will stay, but when I place a second one adjacent to the first, it causes a block update which forces both tracks to disappear.

This should no longer be an issue.

My guess would be the function adding the trades for tracks is in Railcraft/src/main/java/mods/railcraft/common/worldgen/VillagerTradeHandler.java and that it's adding all the tracks available. Maybe low hanging fruit for anyone who feels like they want to contribute.

for (EnumTrack track : EnumTrack.VALUES) {
            if (track.isEnabled())
                addTrade(recipeList, rand, 0.1F, new Offer(track.getItem(), track.recipeOutput - 2, track.recipeOutput + 2), new Offer(Items.emerald, 2, 3));
        }

Add something like EnumTrack#isCraftable() to limit the presense of the track in the creative menu and trade and other survival usages?

I have to rewrite this code for 1.8 anyway. Don't worry about it.

FYI, the creative menu is actually a hardcoded list of variants on all my blocks because I don't like the default sorting very much.