The most basic function for BOFFs is to provide space and ground abilities. From this "BOFFs=gear" point of view, you really don't need that many to play the game effectively.
However, many of us play MMOs for more than just gear/stats requirements, and I think BOFFs are a great way to add a personal touch to one's crew that adds to the game's enjoyment immensely. I have 29 BOFFs - way more than technically needed - but I think it's fun to customize a crew with a diversity of races. I think it's great to have a different set of faces every time I beam down, and to see so many of them on my bridge. I even have them spread out from ensign to commander so I don't have two dozen commanders on my ship or away teams.
Who else takes BOFFs past the "gear" level and makes them part of your personal STO story?
Whilst I wouldn't say I've gone overboard, I do have twice the number needed - one half are only levelled for space, the other for ground. They also have different uniform sets; the space "crew" being rather more formally dressed (Duty dress, except for my First Officer. As I'm an Admiral, I decided that he should really be the captain of the ship, and as the captain of a flagship he should be in dress uniform), and the ground lot dressed more practically for ground combat. I've also done two up as crewman/enlisted (despite the rank that they actually have - they are both commanders technically speaking), whilst the other two are officers (one being a doctor).
I do this also. I got shipboard boffs, away team boffs, boffs who are my department heads and exec. I have some of them tied into my story line and some not. My away teams are not full of commanders but are staggered rank wise.
I also wished I could standardized my crew with my boffs
I actually don't go too terribly overboard with BOff slots (I only just recently bought my first BOff slots ever), but I'll be damned if I don't take great care in making my BOffs into proper characters rather than gear and pets. Every single BOff on every single toon I have has, at the very least, some sort of personality built into them as I craft their appearance. I also take some care to divide my space and ground crews to some degree. All my BOffs are technically ranked to Commander, but I stagger the rank pips they wear to give the appearance otherwise.
As the link under my sig shows, I like my crew. 8') I had dept. heads long before the doff system let us have them. I really want a mode of play where we team with other players AND our boffs, my crew and your crews working toward a goal.