4 is fine i drove with only 3 on each side

 

"driving with 4 out of 5 lug nuts is generally safe for a period of time"

Just about anything is generally safe until it suddenly and unexpectedly wasn't safe any more.

 

looking at the pic looks like you still have the OEM wheels. if you do not and the wheels you are running do not match the axle bore size ie: you do not have the hub centric rings then I would not drive on 4 studs dur to the added vibration

If the wheels have matching bore sizes or you have the hub centric rings then you should be okay. Just check it periodically