Is it incumbent on a family to provide for its old handicapped son and take care of him?

The family and relatives- e.g.brothers- of such a person are obliged to spend on him and take care of him if he didn`t have money of his own.

Is it permissible for men to wear silver bracelets and necklaces?

All Praise is due Allah, The Lord of The Worlds

Men are allowed to wear silver rings, but they aren`t allowed to wear bracelets and necklaces because they imitate women by doing so. And Allah Knows Best.

Is it disliked to clip one`s nails at night, and is it permissible to burn them afterwards?

It is desirable to bury the cut hair and the clipped nails. As for burning clipped nails, there is no evidence forbidding that , but it is better to suffice with the aforesaid ruling-burying cut hair and clipped nails-as it is based on a well known evidence.

Is it permissible to pay the Fitr Zakah(obligatory charity) of Ramadhaan on behalf of a dead person?

The Fitr Zakah of Ramadhaan isn`t due on one who had passed away before the sunset of the last day of Ramadhaan.