1) I'd recommend when dealing with non-anime fandoms to use top and bottom instead of the terms like uke and semi. Others in the fanbase will have no clue what you are taking about and making the effort to use terms they are familiar with always makes communication easier. ;) Others above have covered well the origins and baggage that the terms bring with them and how that doesn't apply well so I won't rehash that.

2) In my porn and smut I don't have a real preference as far as who tops or bottoms. In fact, I'd rather the sex not be limited by those roles. Give me topping from the bottom, bottoming from the tops, sex without penetration - I'm an equal opportunity porn reader. :)

3)One thing I love about this community is how nice and helpful they are.