Possible problems with switching away from Origin...

All of your purchased EA content automatically moves to the EA Desktop App. I have TS4 with all DLC, The Sims Medieval, and TS3 with 2 dlc, and every single bit of it ported over seamlessly. So no, you won't have to repurchase the EA content you already own, and your login stays the same so you all should be able to continue sharing the account. In fact, the only thing I have noticed as different is that the option to purchase dlc as gifts seems to no longer exist.