Could you please make these 4 sentences grammatical?

1 You are guaranteed to get sick if you don't put a coat on./It is guaranteed to make you feel sick.
2 There being a lot of customers doesn't change a thing in my life.
3 If you learn how to do your job in a strict establishment, when you are mutated to a different establishment, one that's more lenient, you'll have an easier time doing your job.
4 The hotel has very little rooms available at the moment/has a very little amount of rooms available.

Thank you
1 first option

2 ok

3 mutated transfered

4 very few rooms (countable noun, mon ami!)
Can someone please help me correct these 4 sentences?

Thank you
 Philip's reply was promoted to an answer.