Reasons why we use joss stick other than polluting the air

1. As an offering to God.
2. As a medium to send a message. Something like a letter but for God.
3. Gathering the spirits of the deceased. Probably when the gate opens during ghost month.
4. Calming our minds and body.
5. Getting rid of bad spirits and bad luck.
6. Praying for good health and prosperity.

Translated from http://pankuoooo.pixnet.net/blog/post/165212832-%E7%87%92%E9%A6%99%E7%9A%84%E6%84%8F%E7%BE%A9

They aren't just pheonix! Meanings and what the pheonix symbolizes.

The pheonix of Chinese legend is a symbol of heaven's favor, virtue and grace, luck and happiness. 

The male pheonix is named 'Feng' and is the yang, solar, fire bird.

The female pheonix is named 'Huang'. It is feminine, yin, and lunar. The feminine aspect denotes beauty, delicacy of feeling, and peace,

The Feng and the Huang together symbolize everlasting love, and as bridal symbol signifies 'inseperable fellowship'. They also symbolizes a duality, the yin and yang, mutual interdependence in the universe.

http://horchang.blogspot.my/2011/03/sze-yah-templekuala-lumpur.html

Idols found at the Sze Ya Temple

Idols found at the temple which is related to question No. 9, What is the hierarchy of the deities and how is it mapped on the layout of the community?

http://www.malaysian-explorer.com/szeYaTemple.html