These at first appear to be a few excerpts from the much longer original talk, which I think is entirely worth reading. On closer examination, though, they seem to be thematically related but not the same; maybe Hamming wrote them at a different time? (Or, more likely, this was someone else’s notes from a Hamming talk, since Hamming probably would have gotten someone to correct all the spelling errors.) Compare, from the OP:

Note that importance of the results of a solution does not make the problem important. In all the 30 years I spent at Bell Telephone Laboratories (before it was broken up) no one to my knowledge worked on time travel, teleportation, or anti-gravity. Why? Because they had no attack on the problem. Thus an important aspect of any problem is that you have a good attack, a good starting place, some reasonable idea of how to begin.

to the corresponding piece from the longer talk transcript:

Let me warn you, `important problem' must be phrased carefully. The three outstanding problems in physics, in a certain sense, were never worked on while I was at Bell Labs. By important I mean guaranteed a Nobel Prize and any sum of money you want to mention. We didn’t work on (1) time travel, (2) teleportation, and (3) antigravity. They are not important problems because we do not have an attack. It’s not the consequence that makes a problem important, it is that you have a reasonable attack. That is what makes a problem important. When I say that most scientists don’t work on important problems, I mean it in that sense.

Contra kghose’s comment, I don’t think it’s particularly tongue-in-cheek, although some parts are maybe a bit blithe about the drawbacks of the course of action he recommends. Nor do I think it is “borne out of an exaggerated opinion of himself”; it is borne of a correct and universally-acknowledged opinion of the great scientists Hamming was studying.

Contra twelvebravo’s comment, Hamming recommends spending a lot of time thinking about things you find interesting and don’t know to be important, just like Feynman; his mention of the Buffon needle problem in the OP is one example, and another is from the longer talk:

When you are famous it is hard to work on small problems. This is what did Shannon in. After information theory, what do you do for an encore? The great scientists often make this error. They fail to continue to plant the little acorns from which the mighty oak trees grow. They try to get the big thing right off. And that isn’t the way things go. So that is another reason why you find that when you get early recognition it seems to sterilize you. In fact I will give you my favorite quotation of many years. The Institute for Advanced Study in Princeton, in my opinion, has ruined more good scientists than any institution has created, judged by what they did before they came and judged by what they did after. Not that they weren’t good afterwards, but they were superb before they got there and were only good afterwards.

I’ve read this before and I wondered how much of this was tongue in cheek and how much of it was borne out of an exaggerated opinion of himself.