Hey peace and love - I put some tips about airport travel in my posting called....how to make your wig look its best. It is around page 7or so.
I think you might be best sewing it down but I did go on the plane with pins in my hair. I just told the travel security right up front what my situation was to avoid the drama. I was held to the side and my hair was inspected so I'm sure they will do the same for you if your wig is not sewn down.
The other question, I'm not sure, I'd check you tube.
Not to discourage you but U part wigs are not that easy to make, its not just sewing the hair it is the cutting and styling. read my post about cutting a lace wig open into a U PART wig. I have videos and links to show you how to do it. It is also in the same posting...how to make your wig look its best.