Not to mention his time as First Lord of the Admiralty.
Well I restricted myself to PM activities. But if we must...
Gallipoli, of course,
No, not "of course"
Gallipoli HAD the potential to dramatically shorten WW1. Whilst it became a failure the actual plan was audacious and could have opened a new front in the war against a stretched enemy whilst also supporting the Russians who were already getting nervous about their revolutionaries. But most of all if it were not for the Gallipoli campaign the Turks would have had far more troops available to fight TE Lawrence and the whole Arabian campaign might well have ended very differently. Further the Turkish navy was basically taken out by Brit submarines so there was no real threat from them for the remainder of the war.
Had the lacklustre General (not a fighting experienced chap) actually pushed forward quickly to take the heights at Gallipoli much may have been different.
Gallipoli was far from the disaster that superficial teaching has made it. As a standalone campaign it certainly was, but in the bigger context it achieved a significant degree of tactical success. Of course, one would prefer it had been a huge military success and had helped end WW1 2 years early but then I'm sure the Huns/Ottomans wish they had flattened the Allies in their campaigns as well.
but then trying the same thing in the next war with Norway,
The Norwegian campaign did a lot of damage to the German navy but overall the result was to get out of a bad situation. At least they got out quickly that time.
As for Coronel, not sure how that one is Chruchill's fault.
Well...he did look grumpy in photos, and made defiant sounding speeches. As a figurehead, he wasn't bad, and they needed a figurehead. If he'd let people who knew what they were doing get on with it, and spent his time in front of cameras and radios...
Zackerly.
His second term was a better reflection of his capability.
SG
