Multiple currencies in broker statements

[Brendan Simon]

I have a broker account (futures & options) and have traded index 
options on the German DAX, E-Mini S&P, FTSE, and Australian S&P.  My 
monthly statements have cash balances and securitiy valuations in the 
various currencies (Euro, USD, GBP, AUD).  My monthly statement also has 
a column/filed called "Base Currency" which is used to consolidate the 
values into my desired currency (AUD in my case).  Each statement has an 
exchange rate specified for each currency, presumably either averaged 
out over the month or the exchange rate on the last day of the month.

* Each month I want to enter the info on my statement into GNU Cash.  (I 
"potentially" want to be able to do it daily with my emailed daily 
statements too).

Ideally I would like my GNU cash to match the base currency fields on my 
statement, but I can't see how this can be done, especially if I use the 
automatic currency updates as they will probably be different values to 
the broker statements.  Also if I have many different brokers they will 
probably use different rates.

* Would it better to use the base currency values and enter them using 
my default currency rather than have multiple currency accounts?
That's what I was doing to record transactions, but I don't think it 
stacks up because the profit or losses of the trading tend to remain in 
foreign currency accounts rather than get automatically transferred 
to/from my base currency.  It seems more accurate to me to keep track of 
things the way they are.  ie. if the broker keeps US accounts, then my 
GnuCash entries should be similar.  Right?

* Is it possible to set different currency rates for each broker?
eg. EUR-AUD (broker1) = x
eg. EUR-AUD (broker2) = y
eg. EUR-AUD (broker3) = y

I've read the online docs and I understand how to have a base currency 
account as a parent account and mulitple currency accounts as 
sub-accounts.  The cash component is easy but the options securities is 
a little trickier (at least for me).

* Is there any documentation or tips on accounting for options.  Options 
on stocks, options on futures, options on indices, etc ???
* Are they just the same as stocks???

Thanks,
Brendan.