Is there a Connection between Sila and Fear?
Fear is considered an unwholesome state, containing as it does aversion (patigha):

paṭighacittuppādavasena hi bhāyanaṃ
Indeed, fear [arises] due to the arising of a mind accompanied by aversion.
-- Vism-T 21.3 (751)

So no, there should be no connection between morality and fear. ottapa, often translated as &quot;fear of wrongdoing&quot;, is a mind state that recoils from doing evil; it is a quality of mind that involves the disinclination to perform evil, not necessarily related to aversion or fear. It is wholesome.
As to practicing morality for selfish reasons, every part of the Buddha's teaching should be practiced to benefit oneself. Helping others can only come through one's own self-improvement. Of course, disregard for the suffering of others can be a sign of cruelty, which is unwholesome, but the two states are mutually independent; you can be focussed on helping yourself without disregarding the suffering of others, or you can be focussed on helping yourself and meanwhile disregarding the suffering of others.

One should first establish oneself in what is proper; then only should one instruct others. Thus the wise man will not be reproached.
...
Let one not neglect one's own welfare for the sake of another, however great. Clearly understanding one's own welfare, let one be intent upon the good.
-- Dhp. 158 &amp; 166 (Buddharakkhita, trans)