If a tennis ball is cooler then the atoms have less energy so it may hypothetically bounce lower than if it was warmer
Very little
the hotter the tennis ball is the higher it will bounce because the molecules are moving faster and the pressure is decreasing. Opposite when it is cold.
When struck by a tennis racket the factor which effects the ball is how much spin is applied to the ball (more specific top spin) and the surface which you play on. For example: hard courts will bounce alot higher then grass courts.
No Minimum Height! :)
3.5ft or 4ft
The official height of a table tennis net is 15.25 cm(6.0 in). Which converts to 0.1525 metre.
5'4"
The height of the net is 1 m height and the height of the racquets may vary according to the model you buy.
(Potential) energy is directly proportional to the release height.
Hot Vs Cold Hot Vs Cold
you don't
Although there is no preset or manufacture recommended temperature at which tennis balls may be stored, they should be stored at room temperatures of between 65 and 75 degrees, with 68 being the ideal, as that is the temperature mandated for testing tennis balls by the International Tennis Federation (the ruling body for tennis; refer to the ITF link, below).