Regarding using a Sunni mosque as a Shia:
1- Can the aasna ashariah (the 12-imam Shias) use a Sunni mosque and pray alongside their Sunni brothers and Sisters?
2- Are they expected to fully observe the Sunni tradition of praying (i.e. crossing arms, closing prayer by saying salam shoulder to shoulder, letting the imam say most zikrs in jama'ah) or can they observe the Shia code of prayer in jamaa'ah?
3- Are they expected to fully observe the Sunni tradition of praying in furadah?
4- Scholarly opinion aside, how are Shias in a mosque perceived by Sunnis?