Arahants, Precepts, Monasticism, & Worldly Things

Namo Buddhaya! I had four questions pertaining to conduct & the Buddha: (I am Theravāda Buddhist) - How could the Buddha have been on this Earth as an Arahant if Arahants can only be reborn in a higher plane (A Heavenly plane) of existences as according to the 4 Stages of Enlightenment? - Is using items within the same familial household without permission (such as a pencil, laptop, or a clothing item from a brothers room) considered a breach of the 2nd Precept? - How is (with all respect) Venerable Yuttadhammo Bhikkhu able to be in the presence of a nun or the nun in his presence if it breaks the monastic rules? (For example (to name one of many): https://www.youtube.com/watch?v=GkmLYAl1p7w ) "Sitting or lying down with a woman or women in a private, secluded place with no other man present is [an offense of Confession.]"(Summarized Paac. 44; BMC p.385) Source: https://www.accesstoinsight.org/lib/authors/ariyesako/layguide.html#alone - How do monks and nuns get their Tipitaka materials, monastic dwellings, and other worldly things while at the same time not being involved with any medium of exchange? Do they ask lay people to do so? Wouldn’t that be requesting for something, which I’m assuming is prohibited too in terms that they accept & don’t request for thing? Please help! Metta to all!!!