odbc update problems?

HI i have a couple of basic questions and one specific question first of all
why would you ever want to use on the connection option to include
oid....this seems bad if you have your tables set up correctly with keys?
Another question is there any way to import relationship type of data in say
Access so you don't have to manually set it up. The last question is..when i
link tables into access and i try to insert a tuple...i have an odbc driver
failure and on my linux box where the database is it says parser: attribute
'salary' is of type 'money' but expression is of type 'float8' how do i cure
this so that i will be able to add entries into the postgres database from
access?

thanks
Brent