It's a string of letters that convey a meaning, so yes, it's a word. It also has the blessing of being listed in most dictionaries.

Both forms, ironic and ironical are valid and in casual settings tend to be used interchangeably. In a more formal sense, one would say a work that uses irony can be describe as ironical, whereas the events themselves are ironic.

It is. "ironic" was a French loanword, but when it was shoehorned into English, forms like "ironically" made the redundant addition of "-al" natural for some. Both have been in common use for many centuries.

I'm still far more used to the terser "ironic" myself though. "ironical" seems alien and strange to me.

It's the ironic way to use the word. Using a word to sound smart but using it incorrectly and mispronouncing it, is ironic. I think.

Apparently so:

http://english.stackexchange.com/questions/5015/ironic-vs-ir...

I thought ironical was the word that describes what one is doing when one makes an ironic statement?

That is to say when someone says something ironic, they are not themselves ironic, rather they are being ironical.