What do we know about the use of the cross in the early (1st and 2nd century) Christianity? I'm more concerned with it's use as a symbol of the faith (inclusion in churches, jewelry, clothing, etc) but would also appreciate info on use in general Christian art as well.
Did home churches have crosses on the wall or did bishops wear crosses on their necks/clothes. Were Christians regularly shown holding crosses in paintings? Was Christ commonly depicted on the cross or was it bare or both?
The reason that you haven't gotten any answers to this (good!) question might be that, to my knowledge, there simply is no archaeological evidence for 1st and 2nd century Christan house churches. The earliest we know of is the 3rd century house church of Dura Europos in Syria, though we know that they existed earlier. But from Rome, f.e., we have no concrete evidence of them pre-312.
The absolute earliest pictorial depiction of a cross in relation to Christianity seems to be the so-called Alexamenos-Graffito, which shows Jesus as a donkey on the cross, found on the Palatine in Rome. This is clearly a work mocking Christianity and its (for contemporary sensitivities) ridiculous belief in a god on a cross. It is commonly dated to late 2nd/early 3rd century, but doesn't really fit into what you're asking about.
Early Christian epitaphs, which appear in greater number from the 3rd century on, show other symbols, commonly dove, anchor or fish (ICHTHYS), or the Chi-Rho, but not the cross. The cross appears more often only from the mid 4th century, but then in increasing frequency.
