ANSWER:

1- This is absolutely baseless. No problem in sitting cross legged. 

If in your culture it is regarded as disrespectful to sit cross legged in front of elders then you should not do it but this is not prohibited in islam. 

QUESTION: The person deserve 1st of my respect said, it’s not permissible to sit cross-legged or ankle-on-knee, half-lotus or MOVE/SWING LEGS while sitting, DOING LIKE THAT IS ARROGANT/Imitating actors. I said it’s not in Islam. But he said, SHOW ME A HADEED PROPHET DID LIKE THIS, HE ALWAYS HUMBLED HIMSELF THINKING ABOUT ALLAH. Is it true? Should I obey?