For example, what if they had taken out the radar intallations by commando raids, sacrificial paradrops, or cooperation with the IRA?
There was that two guys landed by a sub in Northern Ireland, but they ended up in the hands of police immediately. Or, more accurately, landed into waiting hands of a police who was forewarned of their arrival.
On the other subjects, no they didn't. Mostly, the Germans didn't, until later, realize the significance of the radar stations. And then, there were so many of them, so taking a couple would not be really beneficial in the grand scheme of things. Finally, they later tried using Stukas to take out the radars, but they were very easy to repair and replace and not very easy to hit. Or get the Stuka in position to hit it. What with those pesky Spitfires in the way.