What is the "original Buddhism"?

Many Theravada Buddhists do not have a chance to study Tipitaka. They accept the practices and beliefs from their parents. So many of them can be a little off the path, especially if they are surrounded by or mixed with beliefs that focus on deity and prayer.

Buddhist practices and concepts are subtle and can be mistaken or mispracticed so easily, for example, wish (chanda) vs prayer, admiration (puja) vs worship, great being vs god, cycle of births and deaths vs reincarnation, consciousness vs soul, Nibbana vs oblivion etc. Most of Buddha teachings involve practicing or training mind. So a physical act with the same appearance can be a correct practice if one has the right mental state and can be incorrect with the unwise mental state. So my suggestion is for you to do your own research into Buddhism by studying Pali or Tipitaka and find out what the real Buddhism is.

What is the "original Buddhism"?

Pre-sectarian Buddhism is used by some scholars. This is quite a common question particularly by "westerners". It is the Buddhism that existed before the Second Buddhist Council at Vesali about 100 year after the Parinirvana of Lord Buddha. This First schism of the Sangha occurs when the Mahasanghika schools part ways with the Sthaviravadins.

"Don't you want success in life?"

There are two paths in Buddhism, the Mundane Path that your uncle is implying and the Supramundane Path that you are implying. The Mundane Path is concerned with achieving a better rebirth within Samsara and the Supramundane is concerned with liberation from Samsara.

In the Theravada School, Which is the last of the Sthaviravadin Schools http://www.buddhanet.net/e-learning/history/thera_... the Supramundane Path has four stages; Sotapanna, Sakadagami, Anagami and Arahat.

As long as there is impermanence, no self, and nirvana, its Buddhism. these things are understood differently by different sects, but there is no original Buddhism. there are two levels of truth in Buddhism, conventional and ultimate, conventional relating to Buddhism is the cultural expressions of it, but since it is all an expression of the ultimate level of truth, its all Buddhism.

Original buddhism is based off the five nikayas which predate Theravada. It basically says Buddha never denied the Atman, only denied what the Self is not.