A couple of questions for you:
1) What happens when your single server goes down? How long does it take you to get back up and running?
2) What happens if your demand is spiky?
If you're going to use an instance for a year constantly, you need to look at reserved instances. That brings the price down to $3054 for the year which is not bad as you don't pay for electricity or cooling.
With judicious use of semicolons, you could fit all that into a single line.
You might have to scroll horizontally a lot, but it's still a single line!
I've seen this a million times. People with poorly designed relational databases with no thought given to query plans complain that their database is slow. They then migrate said database to a NoSQL solution (typically a document database like MongoDB) and then find that it is still slow! . In a few cases, the NoSQL solution is significantly slower.
The problem is NoSQL encompasses many different types of solutions. Key value stores like Redis are pretty good (key lookups support wildcards!!!) and I use them as an alternative to memcache. Document databases like MongoDB? If you're excited about them because you don't need a schema, you're just asking for carloads of trouble down the line because you've mistakenly bought into the thinking that you can just chuck arbitrary data into Mongo and get it to perform well.
What if you have to use PostgreSQL? I've seen no evidence that it can scale or run multi-master.
Are you high? Instagram (200 million users) uses PostgreSQL. PostgreSQL is web scale
The majority of POS terminals in the wild run Windows XP. This is unlikely to change anytime soon, so I have no idea how Windows XP's official retirement in a few days time will play out as none of the retailers I work with intend to change their tills. This isn't surprising (to people who support POS terminals), as we still see terminals running Windows NT4 (!!!!!!!).
Our advice to retailers is to always have their tills on a separate non-internet facing network. No one really does this though
It's handy having your an office suite on your tablet as it allows you to make quick edits on the go. No one is expecting you to write your thesis on a tablet, but for reviewing documents, writing comments and making small changes having Office on the iPad stupidly useful.
As for Office suites in general, I don't know what it's like where you are but in the UK you're almost guaranteed that to run into MS Office files in whatever job you do. There's no avoiding it even as a techie as your specifications and such are almost certainly written in Word.
Other than professionally modeling...
Look, this is Slashdot. You're not going to find professional models here.
Obviously, with a question like that you're bound to get all sorts of answers. This is my 2 pence worth.