Purity

If one’s beard is thick and covers the skin, he should wash the surface of it only and run his wet fingers through it.

Yes, he can do one.

You can use the same water.

No, whether it is covered or not, this doesn’t affect the wudhu.

You do not have to repeat your wudoo’ after smoking, but you should remove the offensive odour from your mouth with something that will take it away and repent to Allah from such a sin. https://www.youtube.com/watch?v=wiQyi4Yyb5Q

You only need to wash it properly. The seven times and dusting is only when washing utensils that the dog had licked.

This is not necessary.

If a person had sexual impurity and couldn’t remove it, he must use tayammum but once he finds water, he must immediately perform ghusul.

No, you don’t have to do that. Just wash the feet and what is between the toes.

The hadeeth is authentic and the feet must be washed. Wiping can be only applied over socks!