If you do this, you will rebound bad and by day 2 of the vacation look worse than before. 

1) Diet sanely to lose 1-2lb a week.

2) Practice restraint and moderation on the vacation. 

This is a lifestyle, not a diet

It can CERTAINLY help--GREAT combo!

This is the plan for YOU: www.massdiet.com

They are just dextrose, I am not a huge fan for many reasons. This is what I recommend PWO:

1 scoop MTS Whey

1 scoop MTS Carb 10

2 scoops Overtraining Solution

I would avoid them since it is a short term thing and you will lose most gains on the "rebound". I recommend a natural test booster like Barracuda stacked with Insurgent.

It is from the added weight. I would look into foam rolling and pillar prep and go barefoot as much as you can to strengthen your feet. See How to Perform Pillar Prep and Movement Prep For Strength Training

Yes you can. It is food, period

I do not

All you can do is train hard. I am not certain what other factors involved in this will impact your gains.

SCAM! WARNING! The Dangerous Truth About Waist Trainers