A preposition is always followed by a noun or a pronoun:
I went to the store.
I spoke to your father.
In some cases, the infinitive form of a verb acts as a noun:
From Daily Grammar:
To eat is fun. (subject)
I like to eat. (direct object)
A fun thing is to eat. (predicate nominative)
My hope, to travel, never happened. (appositive)
I want nothing but to save. (object of preposition)
In the last example sentence, the preposition is actually but (being used in the sense of except), which is then followed by the infinitive to save that's acting as a noun.
In the example sentences in the question, all three infinitive verbs are being used as verbs; they describe actual actions.
In short, all of the sentences are using to verbally, not prepositionally.