Czy lubi pani kawe z cukrem?

Czy lubi pani kawę z cukrem?
Is Kawa made accusative because it follows the verb LUBI?
Then Cukier is made instrumental because it follows the preposition 'z'?

If I am wrong please correct me.

Any similar examples of short sentences with case changes would be helpful.

I would expect so - ze curkiem. (Z becomes ze before an s, c, z or possibly one or two other sounds). But then you probably know that I'm about as much of an expert on this kind of thing as you are, so someone else probably knows better.

Czy pan lubi kawe z cukrem czy bez cukru?

Word order isn't always that important in Polish but, on some occasions, it definitely is.

I'm at work so can't find the Polish marks on the computer.

"Czy lubi pani kawę z cukrem?"
Above is an exact copy of the sentence on my worksheet.

This is easily explained, ArcticPaul.

The Poles say ze mną simply because it sounds better than z mną. Z tobą is ok.

The same applies to w poniedziałek and we wtorek. Z cukrem is pronounced quickly.

<<Czy lubi pani kawę z cukrem?
Is Kawa made accusative because it follows the verb LUBI?
Then Cukier is made instrumental because it follows the preposition 'z'?>>

You are correct. LUBI is followed by a noun in Acc. because it answers question: kogo, co. Lubię herbatę z mlekiem. Lubię wodę z sokiem. Lubię chleb z serem. Lubię bułkę z masłem, etc. The preposition "Z" is followed by the sixth case (narzędnik), which answers question: kim, czym (in this case: z kim, z czym). Idę z psem, bawię się z kotem, jem kluski z sosem, piję lemoniadę z lodem, etc.

I hope it helps, but truth be known, Polish grammar is not for the faint of heart. :)