Link Silo Structure - Best Practice

I am looking to get peoples' opinions on the best link structure for multiple country information pages for a logistics business.

This is for a "proper" business and needs to have the right balance between giving the website best chance of hitting longtail keywords but not looking too keyword stuffed between the Metatitle, URL & Page.

1st Question

Should a category in a link i.e www.domain.com/category/Australia have a live page with content. I personally think so but many do not.

2nd Question

I have also come across several site where the resulting url has a different category in the url than the actual category it is linked from. i.e

www.domain.com/cat-A displays all the countries but when you actually click on the country the resulting country has a different url structure.

www.domain.com/country/australia where (country is not a live sub page)

I am sure they are not major issues and odd structures have probably been born out of development over the years as the business is developing.

However, we are launching with 50+ country pages so obviously want to get it right first time.

3rd Question

In the industry the serp results for things like "send to Australia" send a parcel to Australia" or "sending parcels to" etc seem to stand out for a few reasons;

a) very few of the results have 100% keywords in all 3 Meta/Url/domain. In fact very few have 100% in any. I assume this is over optimisation at work.

b) I noticed that all top 5-10 results have different keywords in url structure. I assume Google is now picking up on people who try to copy exact title, structure of similar results???

Example result may have:

Send Parcel To Australia with a url structure as www.domain.com/parcel-to/australia

I do not want to copy /parcel-to/ as I already "parcel" in my domain in my opinion.

So I guess my question is if I had;

www.parceldomain.com/send-to/Ausrtralia & a metatitle was "Send a Parcel to Australia" am I pushing things on best practice.

Is includeing send-to in url possible over optimisation.

When I have done SEO for information(ad revenue) sites before it wasn't really an issue but as this is a big business it needs to be right.

Thanks.