That is a tough thing to happen around you. Thanks for sharing.
Re: The unforgivable sin:
Mat 12:31,32 "a He who is not with Me is against Me; and he who does not gather with Me scatters." a Therefore I say to you, any sin and blasphemy shall be forgiven men, but blasphemy against the Spirit shall not be forgiven. "a And whoever shall speak a word against the Son of Man, it shall be forgiven him; but whoever shall speak against the Holy Spirit, it shall not be forgiven him, either in b this age, or in the age to come.
Th atonement of Christ is sufficient for all sin. All sin is interconnected, as one sin leads to, is a causitive factor in other sins. Either it is all forgiven, or none of it is. That is why forgiveness on our part is such a priority - if we hold on to a part of the sin of humanity, the whole thing comes in tow. "Forgive us our trespasses as we forgive those who trespass against us".
This is not universalism. The atonement of Christ is not effective for everyone. Whoever sins against the Holy Spirit (i.e. refuse the atonement of Jesus Christ) has the entire weight of sin on his shoulders.
The eternal destiny of your friend's Dad is not determined by what horrible sins he did/did not commit. No one will live in God's presence in heaven with ANY sin. To be forgiven of any sin is to be forgiven of all sin. All sin must be torn from the soul and turned over to Christ. It is all or nothing. Nothing - to have no sin forgiven - is blasphemy against the Holy Spirit.