Re: overwhelmed w/ electrical
"1: The ground was to the engine, since that is gone for now, where can safely put it? "
DC ground was just a "chassis ground" or negative common, really. Just a convenient place to join all the wires that go to the negative battery post, so join them in any convnient manner and take them to the wing nut that's hopefully on the trolling battery's negative post.
Wing nuts are actually discouraged on cars and boats now, as the quantum physicists have determined that the "wings" are subject to moving from the vibration and causing them to loosen up more often than regular nuts would. Physics, right.
"2: Since the boat is on the hard, do i need a grounding rod? "
Well, for your AC ground, if the marina/yard's AC system is grounded properly, just ensuring that your AC ground wire is properly hooking into that will ensure you have an AC ground. If you really wanted a proper AC ground all your own...yes, in theory you'd pound an 8' long ground rod into the ground. But yards tend to have highly compacted stable ground, odds are you couldn't pound a rod into it even if they weren't looking.