1. When wearing this watch, I'm not hyper conscious of its thickness, but I am very conscious of its thickness. The case is 9.4mm thick, but the dome glass is an additional 10.1mm thick. The watch is SUPER COMFORTABLE because the back of the watch has a cambered sapphire crystal to see the movement. The cambered crystal helps the watch sit low and centered on the middle of your wrist. It also prevents the top-heavy watch from spinning on the wrist. Very comfortable watch!
2. This watch does go well with T-shirts! I don't have any high fashion T-shirts, but It does go well with them. It does not fit under cufflinked French Cuff nor a buttoned barrel cuff. This watch would work well with a cool T-shirt or with a cape!
3. With the COVID 19 situation, I'm definitely not going out very much. I doubt that anyone would notice it walking down the street.