What if Buddha was a liar?

I don't know whether this is allowed here but I don't know where to ask this question. I am someone who examines world religions and the more I read about Buddha, I feel like he was simply another cult-leader. My main objections are the following: 1. Buddha said advanced meditation practitioners acquire supernatural abilities called Iddhis, like going through walls, teleportation, etc. something that even Theravada school admits. Now, the Randi prize is still open, if such powers are possible, let any of the thousands of Buddhist monks worldwide show the ability. I know Buddha said not to get attached to the powers, but if it is true it should be at least demonstratable. Also, Buddha himself didn't show any powers on several occasions when those powers would have been necessary. 2. Buddha preached non-violence to the point where even self defense is not allowed - he told monks to let robbers kill them but not retaliate. This is ridiculous and will definitely lead to the fall of any society if followed. Even Buddha himself didn't follow it - when Devdutta tried to kill him, he made his leg rock solid which hurt Devdutta and he died (an act of self-defense). He also rebuked wars but called kings who used to plunder and have harems as 'righteous'. He also failed to stop wars or support any form of defensive wars. Not very enlightened eh? 3. Buddha laid a lot of stress on donating to the Sangha. The politics of Sangha almost shows that it was like any other cult. Also, for the sake of royal patronage, Buddha seems to have been very diplomatic with kings. Other cults like Jains used to call out Buddhists for enjoying luxurious lives. 4. Buddha's memory of previous lives is strange - if reincarnation is not real, then it automatically makes all these claims a lie - which means Buddha was a liar. Now, one way to establish that his recollections were lies is how he claims of lives millions, billions or even trillions of years ago. Now, unless cyclical Universe is true, lives trillions of years ago can't be true. Lives around 13 billion years ago also cannot be true since the Universe was very early to host life in any form. Millions of years ago, there were no humans on this planet (unless we assume he was talking about lives in alien planets). Altogether, I find Buddha to be just another cult leader and a liar. Given this, all his flowery philosophies of compassion, mercy, non-violence, seems impractical and hollow. What are your response as Buddhists?