I'm still in my 30-day-free playtime and there are things I haven't figured out yet. For example I was wondering about ensign BO skills: Is there any way to upgrade them as my BOs advance?
I'm a Lt. Cmdr. 9 right now and my engineer BO has the turret skill I which places a lvl 15 (or so) turret which was a great help in the beginning but now this skill pretty much became useless since these turrets fall apart the moment some Nausicaans look at it. I guess the same goes for all the other grade I skills, as their effects become more and more insignificant.
I'd like to know if BOs even in the end-game state keep those grade I skills or is there any way to upgrade them, so at some point a BO has four grade III skills?
Nope, at max development, a BO will have 4 of Space & 4 of Ground skills, but it category will have only 1 of each level.
To get the most out of BO, its a combination of keeping them equipped with current level items, choosing a skill combination that can complement each other. And most important, having your character trained up in abilities that support your BO performance. (as your skills have a direct impact on the performance of the BO skills)
As your example shows, a single phaser turret makes easy target practice for the enemy, but imagine 3 engineers in your away team, each deploying 3 turrets apiece plus a minefield to discourage close approach. Plus a dedicated Science/Medic to get everyone alive and healthy to spawn replacement turrets as the battle continues...