Depends..what are you doing? If you're shaving than shaving gel is the obvious answer. If your getting a drink then you'd choose water. If your washing a mirror...shaving

cream.

It will depend on where you are flying from. Generally shaving gel is considered as a liquid and it should be in checked-in luggage, not in hand luggage.

Yes

Yes using the right kind of shaving cream and prepping the area prior to shaving will reduce the likelihood of irritation.

Gillette shaving gel is usually no more than $3.50. I love this stuff and highly recommend it! www.overstockdrugstore.com/products/gillette-for-women-satin-care-shave-gel-with-silk,-dry-skin,-7-oz.html