Just some thoughts, and recaps of ones i've already seen just for emphasis.
1. The Hats. Goodness Gracious the hats. Love them. But now it's kinda lost it's cool/charm. Definitely a Hat Upgrade is in order. On the SIMS series of games, if you purchase furniture, or appliances, rather than selling it, it allows you to "archive" it, or "put it in storage" for future use. Maybe a big ole hat box.
2. Sending Chips needs to be easier and more substantial. 100 chips is only enough to get you into Blackjack (I think). So possibly increase the send amount, and a "send all" option.