Pronouncing ه - ح and س - ص incorrectly

Q: I read a book called Umdat ul Islam written by Abdulaziz bin Hamidullah in Persian some 700 years ago that if one reads the word hamida of sami Allahu liman hamidah with the letter ه instead of ح the salaah becomes faasid. Is this correct, it was also written that if you read Allahumma salli, the word salli with a س and not a ص the salaah is faasid. 

The book in question is it a authorative book? It says also some strange things like that in Jami al Fatawa it is said that if a person makes zina with a animal the animal should be killed and burned, and the person should also burned or a wall should thrown on him.

Sealskinz socks

Q: Are sealskinz socks permissible to wear and be applied the same ruling as leather socks. i.e. is one able to do masaah over these? Do they meet the criteria of not being tied to oneself by any elastic used to manufacture these?

Baseless customs

Q:

  1. My question is that here in India during marriage or engagement the guests give money in the hand or in a envelope to the bride or groom and their parents, grand parents and it is thought bad about some one who does not give anything.
  2. Also before marriage when rishta (the relation ) is finalised then the relatives of both parties give some money to the bride and groom saying that this has to be given to see one another for the first time.

Method of sajdah

Q: When I make sajdah, I am not satisfied and I push my head too hard. I want to know the correct way of making sajda. How much pressure is requried? Where exactly should the floor touch the nose and forehead? Anywhere or some precise position is required?

Cleansing oneself before Salaah

Q: I am a student and I have my college where my entire day passes away. So I have to offer salaah in my college. But at times I have white discharges and my college washrooms are not very clean and easy for me to use. So if I don't wash myself and simply make wudhu will my prayers be valid? As I have to offer 3 times prayer in college that is zohr asr and maghrib. Please advise.

Spending on one's family on the 10th of Muharram

Q: In the Hadith theres is mention to the nearest meaning a person who spends on one's family on the 10th Muharram he will get blessings in sustenance for the whole year. My question is 10th Muharram is on Thursday, is it okay to spend on the family on Wednesday evening to get the virtue and blessings of spending on ones family, because 10th Muharram starts after maghrib on Wednesday till maghrib on Thursday?