I spent 12 years working in the drinks industry and I can say that you are probably more right than your mate, Barks.
When whisky comes from the still it goes into barrels where, as you say, it absorbs the flavours from the charred wood from which they're made. many of these barrels come from the US Bourbon industry, others are used Sherry casks.
If the spirit is going to be made into vodka or gin, and a large proportion of the Scotch Whisky industry's output is, it is re-distilled, or 'rectified'. This so-called 'Rectified Spirit' has the remaining impurities removed and is normally sold in the industry at around 96.5% alcohol by volume. The impurities that are removed at this stage would certainly affect the flavour of the spirit and contribute to the eventual flavour of any whisky.
There are few, if any, distillers of Gin or Vodka in this country who actually make their own spirit. Most, if not all, buy it from whisky distillers or from a few producers of alcohol made from molasses.
So, to answer your initial question i) I wouldn't recommend you drink whisky straight from the still - it will be over 90% alcohol and it wouldn't take a huge amount to kill you. ii) If you water down to a potable level, say 50%, you will notice a flavour, but to nowhere near as great a degree as after it's been in the wood for 12 years. And, depending on where it's been made, that flavour may not be like any whisky you've ever tasted. It will certainly change over the years.