1 - No rule can be applied to all horoscopes. This is a general concept for Ketu’s placement in a chart. If you have other examples where the chart looks a bit different, or the result is different, then you’re also right. The whole horoscope must be seen to check the benefit aspect and affliction.

• Ketu in Leo (5) is good for longevity. It does not matter which house (without affliction)

2 - Finance

Ketu is the Karaka for Moksha (liberation), enlightenment. Generally, Ketu does not support the idea of having material possessions.

2.1 - Ketu does indicate material gains if it’s in a suitable condition, such as in the image above, and the dispositor of Ketu should be strong:

• In Kendra or Mokshatrikona, Ketu should be weak, in the sign of Taurus, AND have at least one benefic association.
• For example, Henry Ford, Ketu 10th house (the strongest house for Ketu), in Taurus, aspect by Jupiter. At the end of his life, he’s indeed moving toward spirituality,
• Or Bill Gates, Ketu in the 12th house, in Taurus
• If not in Kendra, Ketu should be strong in Sagittarius/ Gemini.
• For example, Steve Jobs, Ketu 5th house, Gemini, conjunct Jupiter, aspected by Venus
• Or Jack Ma, Ketu 5th House, Sagittarius

2.2 - Ketu in wealth houses (2, 5, 9, 11) does give wealth if Ketu is associated with a benefic

2.3 - Afflicted Ketu and malefic aspect by Saturn/Mars. You can expect troubles in finance and marriage.

• Ketu is the karaka for peace of mind, enlightenment. If it’s afflicted, then there’s no peace of mind. It’s logical.
• For example, Ketu is alone in the 2nd House, aspected by Saturn, no other benefic aspect, the result is not so good.

3 - The effects of Ketu on personality 

sometimes the positive can also be negative, and vice versa. You decide which one is positive or negative for yourself.A prominent Ketu indicates that

• The native is a loner. That requires a lot of strength to be alone, to handle everything by oneself. The Eagle never flies in a group and looks for shelter when it rains. The eagle flies above the dark cloud to avoid the rain. The wings must be strong enough to do so. Rahu rules 8 basic directions on the map. Ketu has only one direction, which is GOING UPWARD.
• The native never complains, brags, or judges others. They don’t have the time for that, and they don’t like to either. They tend to isolate themselves and focus on what they think is necessary. Ketu does not have a head.
• Ketu only has a body - The native works a lot and with high precision/ accurate timing.
• The person doesn't like when someone shows them sympathy. - For example, they don't know how to react or don't want to react, if someone tell them “I'm so sorry for you”. In their head, they would think, “why sorry? It's life. Everyone goes through difficulties. I am not the only one.” Certain level of detachment is there. Therefore, to them it's not really a loss, because they don't attach to it.
• If these points above are positive to you, then the opposite is the negative side of Ketu.