#1 - Currently, yes. Yet, SC uses this flag: "UsesMultiplePositionsPerSymbolAndTradeAccount". A responsible plugin writer will account for this in case SC adds such a broker. You never know.
e.g. FXCM,LMAX,Gain trading via SC is FIX-based and so is NFA compliant by definition.
By the way, NFA compliance and Zorro's NFA mode are two very different things.
#2 - The idea behind my method is that the bracket-child-orders will sit with the broker. Plugin receives
pool trades and places all
orders as needed, including
bracket stop orders and
bracket limit orders. The user interface will be "trades".