1) It's not designed for Windows, it's approved for Windows - totally different. Most PC hardware works under Ubuntu - after all, Ubuntu was designed on PCs.
2) There are two programs you need, both free and both easy to install - Wine and Wine Doors. (There's a package manager - Synaptic - and it will install both of them.)
3) Yes (under Wine), yes, there are a few and there are a few.
4) You don't have enough RAM to run Windows, but you have plenty to run Ubuntu. Otherwise your hardware is fine.