In the current version there are unfortunately no more weight gain scenes other than the one in the intro. The next update will have several more though.
As for your second question, I've improved on that menu and made it a lot easier to use. For now though you can cheat in money if you set the function to "gd.set", the path to "$" and the value to the amount you want. (Obviously removing the quotation marks)
Hope that makes sense. :)