The first example, naively translated to scheme, results in:

    (define (skip-many a)
      (or (and (a) (skip-many a))
          (void)))

This is not infinite recursion. The Parser monad used in the Haskell version is simply a stream dressed in monadic clothes (and even C has streams a-la FILE*).

As for the second example, the naive translation to scheme is:

    (define (print-n-times n s)
      (cond 
        ((zero? n) (void))
        (else (put-str-ln s)
              (print-n-times (sub1 n) s))))

Here, both Haskell & scheme demonstrate constant memory usage; not because of Monads, or strict/lazy evaluation, but because of tail recursion.

Also, in your first sentence, I think you meant "strict".