Usually devotion is given to Bodhisatvas not deities. Bodhisatvas are Enlightened persons who have taken vows not to enter Nirvana until all sentient beings have gone before them. Therefore, the continue to be reincarnated. The most famous bodhisatvas are Amitabha (Amida), Maitreya and Avalokiteshvara. The latter got conflated with the goddess of wisdom in China and became Kuan Yin.
In the Vajrayana and Indian flavoured Mahayana sects, there is much more devotion to gods/goddesses. They aren't seen as supreme beings, but rather 'protectors' and deities that can offer favours. Vajrayana sects even use oracles and mediums, and attempt to 'tame' various 'gods', and bring them to submission. Read up about the Dorje Shugden controversy, it'll give a bit more insight into deities in Vajrayana Buddhism.
Further, because of the belief in reincarnation, it is believed that former humans can be reborn as deities, and vice versa, so it blurs the line a bit between our understanding of 'gods' and the Buddhist understanding.
The explanation of Buddhist deities you give is very much in line with the Chinese tradition (Ch'an), which is based on an older form of Mahayana and also Taoism. Buddhism is very different for example, between Theravada (no devotion to deities, no Bodhisattvas, salvation relies on one's own effort) and Vajrayana (lots of devotion to many deities and Bodhisattvas, tantras/magic, various shortcuts and 'techniques' to achieve different types of salvation).
Buddhism explicitly denies there is a creator God. Since life is suffering anyone who created it would have to be evil anyhow. It doesn't explicitly deny the existence of other gods but since they are seen as trapped on the wheel of rebirth like humans they are of no use to those who want to get off the merry-go-round.
Buddhism denies a supreme creator God, but acknowledges many deities in the Hindu pantheon.
Also, it's incorrect to say they believe life is 'suffering' in the sense western people understand it, a more apt translation would be to say it's impermanence and change, and expectations that aren't realistic or which don't understand this leads to suffering.
Dukkha - Wikipedia, the free encyclopedia
Obviously not all life is suffering, there is room for happiness and pleasure, and there are many in this life. But impermanence (at least physical) is a fact we all must deal with.