While it says you can add links, are extra links actually available? I've been down this road before!

I have an 8.5” wrist and never need extra links. But if you contact Invicta I’m sure they could accommodate if not possibly eBay.

What is the difference between this model and the ‎invicta men's pro diver quartz watch (30018)?

The 30018 has a solid black face and this 1 has a more "mirrored smoke" color face. Also the 30018 is smaller, almost a ladies watch and this is a mans watch. They are both mens, it also depends on your body frame.

Will it fit a 7.5 inch wrist?

This item has a band length of 185mm or approximately 7.28 inches. If we include the size of the case itself, it should fit a 7.5 inch wrist.

Pro driver not suitable for diving?

Go look at Aragon watches great prices and they do have dive watches! I have one that’s rated at 1000m but never tested it anywhere as I don’t dive. Just a cool watch. Also I believe Invicta has the reserve line that is pretty legit