What is the legitimate legal ruling on a person who married with the intention of evading military service, then abandoned his daughter resulting from that marriage to be raised by a non-Muslim mother? And can he be trusted for marriage despite his showing remorse and changing his behavior for the better?

If the suitor is a man of religion and good character now, he should not be rejected for sins he committed in the past for which he has repented, as what matters is his current state. However, it is not enough for him to inform you about himself; his friends, colleagues, and neighbors should be asked about him, and your family has the right to take their time and ascertain his uprightness. If you are not reassured about his condition and the sincerity of his repentance, then do not advise proceeding with the marriage.