I think that each sect has its own rules/doctrines. Growing up in Gaudiya Vaishnavism many things were restricted. For instance, everyone is vegetarian. Harming or killing animals purposefully or unnecessarily is a great sin. Illicit sex is a sin. Nudity was offensive.
But then a lot of other Hindu sects have different rules based on their interpretation of reality through various great spiritual masters and interpretation of scripture.
Chastity, devotional service (to God), respecting all beings, humility etc. etc. It also depends on one's role in life and duties. In fact, following one's duty is amongst the main teachings in the Bhagavad Gita. An ordinary person is not expected to live as strict a life as an initiated person or mendicant (renounced, monk).
This depends entirely on one's state of consciousness. If one's mind is firmly fixed on God, then nothing material can phase you. Yes, of course material objects can help. For instance, playing devotional songs/prayers using a cd player for example.
But material objects are not really considered 'bad'. It is desiring them, or having attachment to material things that is detrimental to our spiritual progress. But we are not expected to be perfect immediately. A lot of people repress themselves by forcefully giving up certain pleasures. But a lot of these people are not ready to give up these things. Progress is gradual. By trying to skip ahead too quickly, one becomes overly repressed and often fall apart. An example is when a person decides to live the life of a Sanaysi- meaning renouncing material things and devoting all your time to God. These persons are not allowed to associate privately with women or to have sex. If a person is not an advanced soul then this premature giving up of sex often results in the person not being able to cope, and doing something very scandalous.
Anyway, I am sure that others will have better answers for you. I have to go!