For the first question, it's not compulsory at all to use
"Le tengo" instead of
"Yo tengo". It's a matter of choice on the speaker. It is true than in Spanish the subject is usually omitted, but it's not compulsory to do so. I think this answers the first part of your question.
leis a pronoun referring to
miedo al fracaso,
Le tengo instead of
tengodoesn't add any extra meaning to the sentence, and in fact that
leis reiterative and redundant.
On the second part,
al is the contracted form of
a el. This one is however compulsory to use, except in the case of personal names (such as Sara, but including brands that use the word
El in their name, for example). This way,
a el fracasois contracted to