Can I anchor up?
yes, avoid high traffic and high speed areas
Cleanest bathrooms?
park bathrooms are ok, for number 2 I use the resorts 
Wash down centers or Showers?
never used a wash down, most park restrooms have outdoor showers to rinse off
Are the bad currents in the bay?
it moves fastest in narrow places like under the bridges and marina entrances. the main channel can move swiftly as well especially if the wind is going the same direction.