Masaail relating to intimacy

Q: Is it permissible for the wife to masturbate her husband? (Using her hand on him)

Q: Once my wife’s periods finished, we had sexual intercourse before she could take ghusal (bath), really we fear azaab (punishment) of Allah Subhanu Wata’aala on this matter. May Allah forgive me for this and guide me to spend my life according to the Sharia.

Q: I have read that conjugal relationship should be done to the bare minimal to the extent that it should be only once in a lifetime. Also mentioned that looking at the private parts or in a standing position etc. could result in a blind or dumb child etc. mentioned together with a few more repercussions. Is all of this authentic?

Q:  A woman experiences her menses for an indefinite amount every cycle, after e.g. 7 days her bleeding stops. She performs Salaah etc. However at times the bleeding restarts before 10 days... Is conjugal relationship allowed while she is performing Salaah?

Q: Is it allowed for the husband to swallow the "mazi" of his wife, and the wife to swallow the "mazi" of her husband?

Q: To what extent oral sex is allowed in Shariah?