The tool is available at [adwords.google.com...]
No, clicking on any of the ads through the Ad Preview Tool does not charge the business or even record the impression.
Even when you want to check if your ads are showing on Google use the ad preview tool. The reason being when you do a search on Google, you see your ad and don't click, you are recording an impression for your ad but no click and this affects your ad performance.
When you use the ad preview tool, it performs a real search (just like on Google.com), but the clicks or impressions are not recorded.
So now if you want to check competitors' landing pages for the Denver area, you have to go to the URL [google.com...] where the the ads are clickable but it also accrues impressions and clicks.