For #1, it can't hurt but considering the low total volume of water involved (1L over a day), I doubt it makes any significant difference for a healthy person. When the water volume is that small, and your body is thirsting for water, it will absorb all of it.

The one exception I would make is if the person's GI tract is compromised somehow, e.g. they're vomiting or have diarrhea or some stomach bug and the additional electrolytes will assist in fluid absorption. If I have diarrhea, drinking Vitalyte can significantly lessen its severity because the gut can absorb the water instead of letting it "run through you". For me, that works better and quicker than using, say, a binder like Kaopectate.

Also, some products are salty enough to make you thirsty, like Gatorade, which is probably the opposite effect you want. That's great for the company who wants to sell as many bottles of Gatorade as possible, but not good when you have a limited water supply to drink.

For #2, assuming you are making a "large" amount of water available to the wounded person at once, then it probably is more beneficial than straight water, although I'm not sure it makes much practical difference here either given that amount of blood loss.

It can be beneficial to increase the volume of fluid in the circulatory system after blood loss, and pure water would tend to dilute the blood, potentially causing other complications. Also, when giving a large volume of water to drink at once, the ORS can assist in increasing the rate of absorption of all that fluid.

Actually, I'm not sure if your body would want extra fluid to replace the blood volume loss. If your blood vessels constrict to keep up your blood pressure, then there's nowhere for that extra water to go except out through your kidneys. On the other hand, if the person is feeling lightheaded from low blood pressure, it could help.

Note that if the wound may require surgery fairly soon, then drinking water is probably not a good idea due to the risk of vomiting under anesthesia. Increasing fluid volume through an IV would be preferable.