1) No
2) No
The property will simply merge your resevations into one stay (albeit with 3 reservation numbers). If you insist on changing rooms, they will simply perform a room change while you're on property. Similar to if something happened in your room that they couldn't fix (such as the A/C not working).
Unsure of which property you're referring to buy suite upgrades rarely happen automatically for Diamonds, and generally are for short stays.