The default soundfont is "Obsidian", which I believe was designed by Ultrasabers for the Obsidian soundboard but is also loaded as a default font on Diamond sabers. So no, everything is just fine with your Diamond! And Obsidian is actually a pretty decent font IMO, so at least there's that haha
Can these soundboards be wired to work with Neopixle blades?
That's a good question. The board itself might handle it just fine (though at present it wouldn't support scrolling or localized FOC). But one of the things I do know about NeoPixel blades is that they do not like RGB very much. They're perfectly capable of it, but it produces a LOT of heat depending on what color you have running. If you can't safely use RGB mixing, honestly I think it kind of defeats the point of the Diamond controller.
When i program the saber can i or should i remove the batteries asbit is plugged in the computer?
You need to keep the batteries in while programming because otherwise the saber doesn't have any power (unless you have a recharge port in which case you should just be able to plug it into the wall). Make sure your batteries are on full charge before you do this and ESPECIALLY before any firmware updates.