Re: A small correction...
Obviously you're welcome to put ice in any drink you want. It's your drink after all. But putting ice in good single malt whisky is still wrong.
A bit of water is fine. Some whiskies taste amazingly different with the addition of a bit of water, and so you should probably try them both ways before deciding. If I'm going to drink Laphroaig, that's how I'll take it. I also have a bottle of cask strength Talisker that isn't really drinkable without water. In an ideal world the water should be soft and shouldn't be too cold.
The reason not to use ice, is not that it'll water the whisky, but that it'll chill it. Which means you don't get the flavours. Almost all flavour comes from up your nose, the tongue only being able to detect salt, sweet, sour, bitter and umami. You need all those lovely chemicals to be nice and warm, so they can waft up yer hooter, and make niceness.
Which is why I prefer my whisky from a brandy glass - so my hand can warm it up.
If you want to drink something cheap, especially with a mixer, then ice is no problem. But if you're paying double the price (or more) for good quality stuff, then presumably you're drinking for the flavour, and so ice is a no-no.