1 Every time you use a bit of hot water the water tank heats up water to maximum capacity again so that you always have a full tank of ghot water. (Is that how youd use maximum capacity?)
2 I don't know which way I want my body to face when sleeping as both ways don't feel right.

3 Whether a person can rein in the desire for the same gender, to a large extend will depend on his upbringing, edification 

4 An actor has to act a certain way through a show. He has to maintain the same persona that the character possesses in the script. He can't change his way of potraying the caracter haldway throughout the show.

5 How would you say this to sound natural?

6 If you look at him upside down/from upside down, he looks so funny.

Thank you

Philip

“

3.  ???

”

I'll hazard a guess:

he meant "whether a man can keep his desire for specimens of the same sex in check, to a large extent depends on his upbringing, education"