Solid Hardwood, Engineered and Laminate Flooring - Engineered flooring, moisture barrier question, plus more.

I am installing click together enginneered flooring. The flooring is 1/2" thick and will be installing over 1/8" cork to bring it to the same level as my adjacent tile floor. I will be installing it on the main floor which is over an unfinished basement. Do I need any type of moisture barrier under the cork? Also, since I will be floating this floor, does it matter which direction I install it? Would you recommend t-moldings for the transitions to the adjacent tile floor or grout colored caulk?

Typically manufactures recomended running parallel to the longest wall but whatever suits your taste is all that matters considering the least amount of waiste(unless your pockets are full of cash). You dont need vapor barrier over a wood floor base. If you have a moisture problem in the basement id resolve that reguardless.
Use T molding between the same level of flooring .Using a water base grout is introdcing water into the engineered flooring material wich is a nono.

Click together hardwood is designed to be installed as a floating floor, so you need to use the t-moldings to maintain proper expansion space. I do not recommend using a vapor barrier over a wooden subfloor as it can cause moisture to collect in the subfloor which could cause squeaks or soft spots. The direction of the floor should be based on the direction of the sunlight coming into the room- toward the light, unless it will cause the floor to be over 30 feet wide in the direction of the width of the boards. In most hardwood or laminate, most of the expansion occurs across the width of the board, not the length.