If you are sticking with 1 cell, just short the resister. It's a buck driver and doesn't have enough voltage overhead to properly regulate with one cell and an XML2. If you are going to use 2S cells or more, I would recommend taking taking even smaller steps them .1 ohms at a time.
And is not then which resistor. I'm really not as lost as that sounds I just have not even opened the light up yet. So I haven't seen the stock board...
I don’t have a picture of mine, but Here is a picture of a Thorfire C8s driver. Same driver used in my VG10. The R056 is the resistor. I stacked 2 R100’s on top to halve the resistance. ImA4Wheelr is right though, you could just bridge that resistor with solder. I don’t know enough about the circuit, so I’ll defer to him, as to if resistance is needed.
That will depend on a lot of stuff. Most likely current will only increase moderately. Probably will get high 3's. If the Modes get compressed (i.e. the lower modes flow as much current as High Mode), then resistance will need to be added back to get the mode spacing back. Most likely will not be problem with one cell and an XM-L2.
Bringing this back up. I had one of these coming from Banggood, but was officially lost in transient. I just checked Amazon, and they have the vg10 + battery and charger on sale for 40% off $13.79 with coupon code. Also vg10 only for 50% off $7.99, though this does not appear to be Prime, and an extended delivery time. These are 1 use coupons, so I was not eligible for the flashlight only. (I had already purchased one, while waiting on China).