The center console is multiple parts. Begin by opening the actual armrest area of the console. The remove the cup holder insert. Then pull upward on the opened area - should snap up and out easily. After that, you will see 4 screws holding the left/right seat temp, etc. Remove them and the switches should lift out. the next section is the ash tray / gear shift. That has no screws holding it in place but you have to do the following to remove it. On the gear shift lever, pull down on the leather surround so it folds down away from the actual knob. On the lever. there is a little plastic clip just under the knob. Carefully, spread that clip open and it slides off. This will allow you to pull the knob up and off, and remove that section.
There is a link to the FSM for your model year in the FAQ section. It's a bit daunting to search through it, but it contains diagrams with part numbers. You can also use my fav place to find discounted OEM parts:
http://www.infinitipartsonline.com/
They ship fast and all parts are discounted well below what a dealer needs to charge. After you search for a part (by name, not #) you will see a diagram of that part or that area and you can select which specific piece you need. Even when they report it on back-order, it usually ships in a week or so.
As for the cruise control. seems you are setting it correctly. Maybe don't hold the 'set' button down - just get to the speed you want and push it once and let go.