Surely the easiest way is to just carry on your USB stick the latest installers of the various apps you may need to install on the machine you are working on.
If you want to actually install some apps on your USB stick and run them from there,
here's one starting point.
Also don't forget the potential risk of carrying an infection back to your own PC if you plug your USB stick into someone else's infected PC.
Regarding question 2. - you may find something contained in
this thread of use to get you started.