I like to protect a sensitive circuit of mine with a shield. I don't have a picture but basically, I have put together a 1mm thick ground rectangle on top layer and I will place the shield on top of this such that it will contact to this ground trace.

I have some concerns.

1. am I creating a ground loop by doing this?
2. If I don't use the shield, am I making an antenna that will pick up noise?
3. What is the recommended practice for this type of shield?

Actually, I like to connect the shield at a single point but a hardware person who has more experience insists that he like to have a full rectangular ground exposes so that shield can touch to the ground at every point.

Experts, please weigh in.