Night sights: ~$100, maybe $150 installed by a 'smith
Accuracy: Yes, many of the WC pistols will shoot 1.5" at 25+ yards. Do you really need that? If you like the idea of night sights, I'm guessing this might be used as a defensive pistol. If so, what's the practical difference between a Bill Wilson Special and a Colt Commander at 7 yards? My answer would be "None."
Life-time warranty: One of the reasons many of us have a love-hate relationship with the 1911 is that we often *hate* them when we first get them--they can be finicky--however, once they're "dialed in," most seem to run confidently thereafter. So, in assessing the value of this lifetime warranty, factor in the probabilities of (a) are you really going to need it post-6 months of your purchase date and (b) if "Yes" to (a), how often?
Well, my prejudice is probably leaking out: I can't really see the justification of paying WC prices, when there's a wonderful platform gun like the LWC to purchase. Yes, you may have to add some of the bells & whistles yourself ('smith), but I still think you're money ahead by doing so.
PS I purposefully ignored the issue of Colt's firing pin safety, because I think it's irrelevant in the CCW context.