As long as you have all the required 120v outlets, I would not have any serious problem with additional 240v outlets as long as they were NRTL approved (Probably TUV in Europe). The real answer would come from your local AHJ tho. I tend to agree about the issues with the grounded conductor thing. As long as your equipment has 2 pole power switches and it can handle the difference in frequency and voltage it should be OK.
OTOH anything with a wide mouth power supply like that should run on 120v. (mostly electronics)
Your tea pot should really get the water going at 245 or even 250v (not unusual here) if it didn't burn up.
How much European equipment are we talking about here? How many outlets would you need? This really sounds expensive and it would be cheaper to just buy 120v equipment in most cases. When you start pricing 240v GFCIs you will see what I mean and that is in addition to a bunch of extra wire, boxes and devices.
They will not let you have those British ring circuits tho
