I have some warn premiums and the conversion kit on the way. ... Can you guys give me some advice on this matter?
Cancel the order & leave the stock Warn Premium auto hub locks in it.
Will the wheel come off?
Sure, if you remove the lug nuts.
Does the front driveshaft spin when driving in 2wd?
Depends whether the hubs are locked. Follow the instructions in the owner's manual, owner guide, &/or driver's sun visor.
Is there something I can do to get another month out of it safely?
Don't drink & drive.
The hub locks have NOTHING to do with the hub staying on the spindle; they ONLY connect the hub to the axle stub shaft. You can remove the dust cap (the part you're seeing) AND the lock body, and drive 10Kmi safely. Eventually, the contamination in the wheel bearings will stop you, but nothing is gonna fall off.
All you have to do is clean out the hub, and reinstall the lock body so it's as far INSIDE the hub as possible. Make sure the outer lock ring fully engages the groove, and that will keep the dust cap secure.
For more info & lots of pics, click my black Bronco in my signature (BELOW) and read the captions in the Brakes & Hubs album.