What does Litecoin offer over Bitcoin?
Well, Litecoin's main aim is to make mining easier for the common man.

The problem with pure SHA-256 mining is that it is not very hard to design hardware that can perform mining at an astonishing speed. We can see this with the currently very much ongoing rise of the ASIC mining industry.

Since scrypt is more complex when it comes to hardware - scrypt not only requires many processor cycles, but also requires intensive memory use - it is harder to design hardware specifically for scrypt mining.

The result of this is that Litecoin mining will be profitable for the average joe for a longer period of time than Bitcoin mining did, when it would be adopted just as fast. Since it does not, the arrival of dedicated scrypt mining hardware will be even more deferred, to the benefit of the miners.

Besides this, I have to agree with you that the other differences between Litecoin and Bitcoin are only minor. Total currency is really not that important since both are very divisible. And faster confirmations are not required either, most Bitcoin transactions are considered valid upon first notice, since it is hard to perform a double-spend attack. (Note that you should better require a transaction to have a fee included when you want to consider it confirmed upon first notice.)
Also, after one confirmation, pretty much all transactions can be considered final.