2) in the face of difficulties maybe you can have a hard time maintaining (keeping) your pride, depending of course on what the difficulties are; but it doesn't make sense to have a hard time attaining (to succeed in getting) your pride. To choose attaining would make nonsense of a sentence which, in any case, doesn't seem to make much sense.
3) In this sentence, both structures are possible.
4) Here, (a) is not correct because "dare not" forms take the infinitive without "to"*.
*A.J.Thomson and A.V. Martinet, “A Practical English Grammar”, Fourth Edition, rubric 161
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