Welcome to the forum.

a. If weight is not an issue, go with the rack and ez wheels or skate wheels as the bike will roll much better.

b. I would recommend neither. There's plenty of cheaper lighting solutions on the market and gong with separate pieces allows you to change what you use in the future.

c. Really is personal preference. I have read somewhere that the clear is showing rust, but you need to ask yourself if you will be riding in harsh conditions. If not, then it is irrelevant.