New Member and new boat owner!! Have a couple questions

Ok yall... Names Ross and I just bought a 2000 Moomba Kamberra with what I assume is the factory tower on it. I guess its just aluminum but its filthy and dull and i know its oxidized and that its just gonna go right back to that look but what can I use to clean it up and make it look better? Also, I need to route wires through the tower, I have read how to do the vacuum trick but my question is.. Is it ok to drill a hole into the side of the boat from the inside where the tower bolts to the boat? I know there are already 4 bolt holes there but i just feel like i shouldnt be drilling holes into the boat lol. And last is a question about the V-drive. What is the best fluid to use in it and how do i service the thing? This is my first V-drive. And I just remembered one more... Hydrolic fluid for the trim tab??? What should I put in there? Thanks for any advice yall can give me on the boat and all that good stuff!!!