Sorry for the newb question but you have to learn somewhere.
So as a Luitenant I trained my ensign BOs in certain skills, some up to level 9.
I then went to the BO trainer contact on starbase and selected a couple new skills for some of my BOs (for example, I replaced tachyon beam with tractor beam). Now these new skills need to be trained up with BO skill points.
Question: did I completely waste valuable skill points on lowbie BO skills? At the time it seemed like the thing to do, but are these skills wasted, or does anyone ever use those original BO skills again? They were ensign-level skills; won't they just be made useless by Luitenant-level BO skills, captain-level skills, and so on?
If this is the case, is it better to hold all your BO skill points till the end game, and then spend them there?