It's very possible. Some people even do teach themselves these things better than school do, and there are plenty of books out there on all those subjects.

Unless you are a genius, it will take you a long time. Probably longer than if you went to school.

course you can, but its likely the programs you write wont be very good

Learning how to program yourself you are very likely to fall into bad habits, and once you have got into "your" way of thinking its difficult to get out of it.

There are always several different ways to achieve the same result. some will be good, and some cr//p

Teaching yourself you are more likely to write cr//p ones

Go to college its likely they will teach you how to write good ones.

I write very sophisticate software on the .net framework and have taken not one programming class in my life. Yea it possible. Get the proper programming suites and dig in. When you get stuck there is always google.