In My understanding SMBC is one of the most difficult card to have.
According to Japanese BBS, difficulty will be (Easy) Sony Finance(Elio)<JCB<SMBC<Diners (Hard).

2) You should include copy of your foreign registration card.
3) Banking loan would considered to be negative and lower you credit score.
7) If you are self employee it is also considered negeative in Japan.

Sony Finace is said to be easy to own, but I do not know about their policy for foreigners.