Abba S – +1 except:
1.If you stay up all night, you have to wash (halacha l’maaseh at least). The question is on the bracha.
2. you are supposed to wash before you use the bathroom because your hands may have ruach ra’ah on them. It is correct that you should say the bracha only after using the bathroom.
3. Most poskim say that you are allowed to wash in the bathroom because today’s bathrooms aren’t real bathrooms. On a plane where there is no other option, it is certainly fine.
4. It is better to use a cup, but if you don’t have one it is okay as long as it’s koach gavra and 3 times over each hand.